How can I align this longtable?

Question

I have enumerate

\documentclass[12pt,a4paper]{article}
\usepackage{fouriernc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{enumerate}
\usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry}
\begin{document}
\begin{enumerate}[\quad 1)]
\item $y =  (x-5)\cdot \sqrt{x^2+7 x+10}$, \quad $y'=\dfrac{4 x^2+11 x-15}{2  \sqrt{x^2+7 x+10}}$. \hfill Answer. $x=1.$ \item $y = (x-4)\cdot \sqrt{x^2+6 x+5}$, \quad $y'=\dfrac{2 x^2+5 x-7}{\sqrt{x^2+6 x+5}}$. \hfill  Answer. $x=1.$ \item $y = (x-1)\cdot \sqrt{x^2-16 x+60}$, \quad $y'=\dfrac{2 x^2-25 x+68}{\sqrt{x^2-16 x+60}}$. \hfill Answer. $x=4.$ \item $y = (x+1)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{2 x^2-17 x+26}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=2.$ \item $y = (x+1)\cdot \sqrt{x^2-15 x+54}$, \quad $y'=\dfrac{4 x^2-43 x+93}{2 \sqrt{x^2-15 x+54}}$. \hfill Answer. $x=3.$ \item $y = (x+2)\cdot \sqrt{x^2-10 x+21}$, \quad $y'=\dfrac{2 x^2-13 x+11}{\sqrt{x^2-10 x+21}}$. \hfill Answer. $x=1.$ \item $y = (x+2)\cdot \sqrt{x^2-13 x+40}$, \quad $y'=\dfrac{4 x^2-35 x+54}{2 \sqrt{x^2-13 x+40}}$. \hfill Answer. $x=2.$ \item $y = (x+3)\cdot \sqrt{x^2-8 x+12}$, \quad $y'=\dfrac{x (2 x-9)}{\sqrt{x^2-8 x+12}}$. \hfill Answer. $x=0.$ \item $y = (x+3)\cdot \sqrt{x^2-11 x+28}$, \quad $y'=\dfrac{4 x^2-27 x+23}{2 \sqrt{x^2-11 x+28}}$. \hfill Answer. $x=1.$ \item $y = (x+4)\cdot \sqrt{x^2-6 x+5}$, \quad $y'=\dfrac{2 x^2-5 x-7}{\sqrt{x^2-6 x+5}}$. \hfill Answer. $x=-1.$ \item $y = (x+4)\cdot \sqrt{x^2-9 x+18}$, \quad $y'=\dfrac{x (4 x-19)}{2 \sqrt{x^2-9 x+18}}$. \hfill Answer. $x=0.$ \item $y = (x+5)\cdot \sqrt{x^2-7 x+10}$, \quad $y'=\dfrac{4 x^2-11 x-15}{2 \sqrt{x^2-7 x+10}}$. \hfill Answer. $x=-1.$ \item $y = (x+6)\cdot \sqrt{x^2-2 x-3}$, \quad $y'=\dfrac{2 x^2+3 x-9}{\sqrt{x^2-2 x-3}}$. \hfill Answer. $x=-3.$ \item $y = (x+6)\cdot \sqrt{x^2-5 x+4}$, \quad $y'=\dfrac{4 x^2-3 x-22}{2 \sqrt{x^2-5 x+4}}$. \hfill Answer. $x=-2.$ \item $y = (x+7)\cdot \sqrt{x^2-4}$, \quad $y'=\dfrac{2 x^2+7 x-4}{\sqrt{x^2-4}}$. \hfill Answer. $x=-4.$ \item $y = (x+8)\cdot \sqrt{x^2+2 x-3}$, \quad $y'=\dfrac{2 x^2+11 x+5}{\sqrt{x^2+2 x-3}}$. \hfill Answer. $x=-5.$ \item $y = (x+8)\cdot \sqrt{x^2-x-2}$, \quad $y'=\dfrac{4 x^2+13 x-12}{2 \sqrt{x^2-x-2}}$. \hfill Answer. $x=-4.$ \item $y = (x+8)\cdot \sqrt{x^2-12 x+20}$, \quad $y'=\dfrac{2 \left(x^2-5 x-14\right)}{\sqrt{x^2-12 x+20}}$. \hfill Answer. $x=-2.$ \item $y = (x+9)\cdot \sqrt{x^2+x-2}$, \quad $y'=\dfrac{4 x^2+21 x+5}{2 \sqrt{x^2+x-2}}$. \hfill Answer. $x=-5.$ \item $y = (x+9)\cdot \sqrt{x^2-10 x+9}$, \quad $y'=\dfrac{2 \left(x^2-3 x-18\right)}{\sqrt{x^2-10 x+9}}$. \hfill Answer. $x=-3.$ \item $y = (x+10)\cdot \sqrt{x^2+6 x+5}$, \quad $y'=\dfrac{2 x^2+19 x+35}{\sqrt{x^2+6 x+5}}$. \hfill Answer. $x=-7.$ \item $y = (x+10)\cdot \sqrt{x^2-8 x-20}$, \quad $y'=\dfrac{2 \left(x^2-x-30\right)}{\sqrt{x^2-8 x-20}}$. \hfill Answer. $x=-5.$ \item $y = (x+10)\cdot \sqrt{x^2-14 x+40}$, \quad $y'=\dfrac{2 x^2-11 x-30}{\sqrt{x^2-14 x+40}}$. \hfill Answer. $x=-2.$ \item $y = (2 x-5)\cdot \sqrt{x^2-12 x+35}$, \quad $y'=\dfrac{4 x^2-41 x+100}{\sqrt{x^2-12 x+35}}$. \hfill Answer. $x=4.$ \item $y = (2 x-3)\cdot \sqrt{x^2+4 x+3}$, \quad $y'=\dfrac{x (4 x+9)}{\sqrt{x^2+4 x+3}}$. \hfill Answer. $x=0.$ \item $y = (2 x-3)\cdot \sqrt{x^2-10 x+24}$, \quad $y'=\dfrac{4 x^2-33 x+63}{\sqrt{x^2-10 x+24}}$. \hfill Answer. $x=3.$ \item $y = (2 x-2)\cdot \sqrt{x^2-16 x+60}$, \quad $y'=\dfrac{2 \left(2 x^2-25 x+68\right)}{\sqrt{x^2-16 x+60}}$. \hfill Answer. $x=4.$ \item $y = (2 x-1)\cdot \sqrt{x^2+6 x+8}$, \quad $y'=\dfrac{4 x^2+17 x+13}{\sqrt{x^2+6 x+8}}$. \hfill Answer. $x=-1.$ \item $y = (2 x-1)\cdot \sqrt{x^2-8 x+15}$, \quad $y'=\dfrac{4 x^2-25 x+34}{\sqrt{x^2-8 x+15}}$. \hfill Answer. $x=2.$ \item $y = (2 x+1)\cdot \sqrt{x^2+8 x+15}$, \quad $y'=\dfrac{4 x^2+25 x+34}{\sqrt{x^2+8 x+15}}$. \hfill Answer. $x=-2.$ \item $y = (2 x+1)\cdot \sqrt{x^2-6 x+8}$, \quad $y'=\dfrac{4 x^2-17 x+13}{\sqrt{x^2-6 x+8}}$. \hfill Answer. $x=1.$ \item $y = (2 x+2)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{4 x^2-34 x+52}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=2.$ \item $y = (2 x+2)\cdot \sqrt{x^2-15 x+54}$, \quad $y'=\dfrac{4 x^2-43 x+93}{\sqrt{x^2-15 x+54}}$. \hfill Answer. $x=3.$ \item $y = (2 x+3)\cdot \sqrt{x^2-4 x+3}$, \quad $y'=\dfrac{x (4 x-9)}{\sqrt{x^2-4 x+3}}$. \hfill Answer. $x=0.$ \item $y = (2 x+4)\cdot \sqrt{x^2-10 x+21}$, \quad $y'=\dfrac{4 x^2-26 x+22}{\sqrt{x^2-10 x+21}}$. \hfill Answer. $x=1.$ \item $y = (2 x+4)\cdot \sqrt{x^2-13 x+40}$, \quad $y'=\dfrac{4 x^2-35 x+54}{\sqrt{x^2-13 x+40}}$. \hfill Answer. $x=2.$ \item $y = (2 x+6)\cdot \sqrt{x^2-8 x+12}$, \quad $y'=\dfrac{2 x (2 x-9)}{\sqrt{x^2-8 x+12}}$. \hfill Answer. $x=0.$ \item $y = (2 x+6)\cdot \sqrt{x^2-11 x+28}$, \quad $y'=\dfrac{4 x^2-27 x+23}{\sqrt{x^2-11 x+28}}$. \hfill Answer. $x=1.$ \item $y = (2 x+7)\cdot \sqrt{x^2-1}$, \quad $y'=\dfrac{4 x^2+7 x-2}{\sqrt{x^2-1}}$. \hfill Answer. $x=-2.$ \item $y = (2 x+7)\cdot \sqrt{x^2-14 x+40}$, \quad $y'=\dfrac{4 x^2-35 x+31}{\sqrt{x^2-14 x+40}}$. \hfill Answer. $x=1.$ \item $y = (2 x+8)\cdot \sqrt{x^2-6 x+5}$, \quad $y'=\dfrac{2 \left(2 x^2-5 x-7\right)}{\sqrt{x^2-6 x+5}}$. \hfill Answer. $x=-1.$ \item $y = (2 x+8)\cdot \sqrt{x^2-9 x+18}$, \quad $y'=\dfrac{x (4 x-19)}{\sqrt{x^2-9 x+18}}$. \hfill Answer. $x=0.$ \item $y = (2 x+9)\cdot \sqrt{x^2-12 x+27}$, \quad $y'=\dfrac{x (4 x-27)}{\sqrt{x^2-12 x+27}}$. \hfill Answer. $x=0.$ \item $y = (2 x+10)\cdot \sqrt{x^2-7 x+10}$, \quad $y'=\dfrac{4 x^2-11 x-15}{\sqrt{x^2-7 x+10}}$. \hfill Answer. $x=-1.$ \item $y = (3 x-5)\cdot \sqrt{x^2+8 x+15}$, \quad $y'=\dfrac{6 x^2+31 x+25}{\sqrt{x^2+8 x+15}}$. \hfill Answer. $x=-1.$ \item $y = (3 x-5)\cdot \sqrt{x^2+6 x+5}$, \quad $y'=\dfrac{2 x (3 x+11)}{\sqrt{x^2+6 x+5}}$. \hfill Answer. $x=0.$ \item $y = (3 x-5)\cdot \sqrt{x^2-9 x+20}$, \quad $y'=\dfrac{12 x^2-91 x+165}{2 \sqrt{x^2-9 x+20}}$. \hfill Answer. $x=3.$ \item $y = (3 x-4)\cdot \sqrt{x^2+3 x+2}$, \quad $y'=\dfrac{x (12 x+19)}{2 \sqrt{x^2+3 x+2}}$. \hfill Answer. $x=0.$ \item $y = (3 x-4)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{2 \left(3 x^2-29 x+60\right)}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=3.$ \item $y = (3 x-4)\cdot \sqrt{x^2-14 x+48}$, \quad $y'=\dfrac{6 x^2-67 x+172}{\sqrt{x^2-14 x+48}}$. \hfill Answer. $x=4.$ \item $y = (3 x-3)\cdot \sqrt{x^2-16 x+60}$, \quad $y'=\dfrac{3 \left(2 x^2-25 x+68\right)}{\sqrt{x^2-16 x+60}}$. \hfill Answer. $x=4.$ \item $y = (3 x-2)\cdot \sqrt{x^2-7 x+12}$, \quad $y'=\dfrac{12 x^2-67 x+86}{2 \sqrt{x^2-7 x+12}}$. \hfill Answer. $x=2.$ \item $y = (3 x-1)\cdot \sqrt{x^2+5 x+6}$, \quad $y'=\dfrac{12 x^2+43 x+31}{2 \sqrt{x^2+5 x+6}}$. \hfill Answer. $x=-1.$ \item $y = (3 x-1)\cdot \sqrt{x^2-10 x+21}$, \quad $y'=\dfrac{6 x^2-46 x+68}{\sqrt{x^2-10 x+21}}$. \hfill Answer. $x=2.$ \item $y = (3 x-1)\cdot \sqrt{x^2-12 x+35}$, \quad $y'=\dfrac{6 x^2-55 x+111}{\sqrt{x^2-12 x+35}}$. \hfill Answer. $x=3.$ \item $y = (3 x+1)\cdot \sqrt{x^2-5 x+6}$, \quad $y'=\dfrac{12 x^2-43 x+31}{2 \sqrt{x^2-5 x+6}}$. \hfill Answer. $x=1.$ \item $y = (3 x+2)\cdot \sqrt{x^2+7 x+12}$, \quad $y'=\dfrac{12 x^2+67 x+86}{2 \sqrt{x^2+7 x+12}}$. \hfill Answer. $x=-2.$ \item $y = (3 x+2)\cdot \sqrt{x^2-8 x+12}$, \quad $y'=\dfrac{6 x^2-34 x+28}{\sqrt{x^2-8 x+12}}$. \hfill Answer. $x=1.$ \item $y = (3 x+2)\cdot \sqrt{x^2-10 x+24}$, \quad $y'=\dfrac{6 x^2-43 x+62}{\sqrt{x^2-10 x+24}}$. \hfill Answer. $x=2.$ \item $y = (3 x+3)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{6 x^2-51 x+78}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=2.$ \item $y = (3 x+3)\cdot \sqrt{x^2-15 x+54}$, \quad $y'=\dfrac{3 \left(4 x^2-43 x+93\right)}{2 \sqrt{x^2-15 x+54}}$. \hfill Answer. $x=3.$ \item $y = (3 x+4)\cdot \sqrt{x^2-3 x+2}$, \quad $y'=\dfrac{x (12 x-19)}{2 \sqrt{x^2-3 x+2}}$. \hfill Answer. $x=0.$ \item $y = (3 x+5)\cdot \sqrt{x^2+9 x+20}$, \quad $y'=\dfrac{12 x^2+91 x+165}{2 \sqrt{x^2+9 x+20}}$. \hfill Answer. $x=-3.$ \item $y = (3 x+5)\cdot \sqrt{x^2-6 x+5}$, \quad $y'=\dfrac{2 x (3 x-11)}{\sqrt{x^2-6 x+5}}$. \hfill Answer. $x=0.$ \item $y = (3 x+5)\cdot \sqrt{x^2-8 x+15}$, \quad $y'=\dfrac{6 x^2-31 x+25}{\sqrt{x^2-8 x+15}}$. \hfill Answer. $x=1.$ \item $y = (3 x+6)\cdot \sqrt{x^2-10 x+21}$, \quad $y'=\dfrac{6 x^2-39 x+33}{\sqrt{x^2-10 x+21}}$. \hfill Answer. $x=1.$ \item $y = (3 x+6)\cdot \sqrt{x^2-13 x+40}$, \quad $y'=\dfrac{3 \left(4 x^2-35 x+54\right)}{2 \sqrt{x^2-13 x+40}}$. \hfill Answer. $x=2.$ \item $y = (3 x+8)\cdot \sqrt{x^2-6 x+8}$, \quad $y'=\dfrac{x (6 x-19)}{\sqrt{x^2-6 x+8}}$. \hfill Answer. $x=0.$ \item $y = (3 x+9)\cdot \sqrt{x^2-8 x+12}$, \quad $y'=\dfrac{3 x (2 x-9)}{\sqrt{x^2-8 x+12}}$. \hfill Answer. $x=0.$ \item $y = (3 x+9)\cdot \sqrt{x^2-11 x+28}$, \quad $y'=\dfrac{3 \left(4 x^2-27 x+23\right)}{2 \sqrt{x^2-11 x+28}}$. \hfill Answer. $x=1.$ \item $y = (3 x+10)\cdot \sqrt{x^2-12 x+20}$, \quad $y'=\dfrac{2 x (3 x-22)}{\sqrt{x^2-12 x+20}}$. \hfill Answer. $x=0.$ \item $y = (3 x+10)\cdot \sqrt{x^2-16 x+60}$, \quad $y'=\dfrac{2 \left(3 x^2-31 x+50\right)}{\sqrt{x^2-16 x+60}}$. \hfill Answer. $x=2.$ \item $y = (4 x-5)\cdot \sqrt{x^2-14 x+40}$, \quad $y'=\dfrac{8 x^2-89 x+195}{\sqrt{x^2-14 x+40}}$. \hfill Answer. $x=3.$ \item $y = (4 x-5)\cdot \sqrt{x^2-18 x+80}$, \quad $y'=\dfrac{8 x^2-113 x+365}{\sqrt{x^2-18 x+80}}$. \hfill Answer. $x=5.$ \item $y = (4 x-4)\cdot \sqrt{x^2-16 x+60}$, \quad $y'=\dfrac{4 \left(2 x^2-25 x+68\right)}{\sqrt{x^2-16 x+60}}$. \hfill Answer. $x=4.$ \item $y = (4 x-2)\cdot \sqrt{x^2+6 x+8}$, \quad $y'=\dfrac{8 x^2+34 x+26}{\sqrt{x^2+6 x+8}}$. \hfill Answer. $x=-1.$ \item $y = (4 x-2)\cdot \sqrt{x^2-8 x+15}$, \quad $y'=\dfrac{8 x^2-50 x+68}{\sqrt{x^2-8 x+15}}$. \hfill Answer. $x=2.$ \item $y = (4 x-1)\cdot \sqrt{x^2-12 x+27}$, \quad $y'=\dfrac{8 x^2-73 x+114}{\sqrt{x^2-12 x+27}}$. \hfill Answer. $x=2.$ \item $y = (4 x-1)\cdot \sqrt{x^2-16 x+63}$, \quad $y'=\dfrac{8 x^2-97 x+260}{\sqrt{x^2-16 x+63}}$. \hfill Answer. $x=4.$ \item $y = (4 x+2)\cdot \sqrt{x^2+8 x+15}$, \quad $y'=\dfrac{8 x^2+50 x+68}{\sqrt{x^2+8 x+15}}$. \hfill Answer. $x=-2.$ \item $y = (4 x+2)\cdot \sqrt{x^2-6 x+8}$, \quad $y'=\dfrac{8 x^2-34 x+26}{\sqrt{x^2-6 x+8}}$. \hfill Answer. $x=1.$ \item $y = (4 x+3)\cdot \sqrt{x^2-10 x+16}$, \quad $y'=\dfrac{8 x^2-57 x+49}{\sqrt{x^2-10 x+16}}$. \hfill Answer. $x=1.$ \item $y = (4 x+3)\cdot \sqrt{x^2-14 x+48}$, \quad $y'=\dfrac{8 x^2-81 x+171}{\sqrt{x^2-14 x+48}}$. \hfill Answer. $x=3.$ \item $y = (4 x+4)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{4 \left(2 x^2-17 x+26\right)}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=2.$ \item $y = (4 x+4)\cdot \sqrt{x^2-15 x+54}$, \quad $y'=\dfrac{2 \left(4 x^2-43 x+93\right)}{\sqrt{x^2-15 x+54}}$. \hfill Answer. $x=3.$ \item $y = (4 x+6)\cdot \sqrt{x^2-4 x+3}$, \quad $y'=\dfrac{2 x (4 x-9)}{\sqrt{x^2-4 x+3}}$. \hfill Answer. $x=0.$ \item $y = (4 x+7)\cdot \sqrt{x^2-8 x+7}$, \quad $y'=\dfrac{x (8 x-41)}{\sqrt{x^2-8 x+7}}$. \hfill Answer. $x=0.$ \item $y = (4 x+7)\cdot \sqrt{x^2-12 x+35}$, \quad $y'=\dfrac{8 x^2-65 x+98}{\sqrt{x^2-12 x+35}}$. \hfill Answer. $x=2.$ \item $y = (4 x+8)\cdot \sqrt{x^2-10 x+21}$, \quad $y'=\dfrac{8 x^2-52 x+44}{\sqrt{x^2-10 x+21}}$. \hfill Answer. $x=1.$ \item $y = (4 x+8)\cdot \sqrt{x^2-13 x+40}$, \quad $y'=\dfrac{2 \left(4 x^2-35 x+54\right)}{\sqrt{x^2-13 x+40}}$. \hfill Answer. $x=2.$ \item $y = (5 x-5)\cdot \sqrt{x^2-16 x+60}$, \quad $y'=\dfrac{5 \left(2 x^2-25 x+68\right)}{\sqrt{x^2-16 x+60}}$. \hfill Answer. $x=4.$ \item $y = (5 x-3)\cdot \sqrt{x^2+7 x+10}$, \quad $y'=\dfrac{20 x^2+99 x+79}{2 \sqrt{x^2+7 x+10}}$. \hfill Answer. $x=-1.$ \item $y = (5 x-3)\cdot \sqrt{x^2-11 x+30}$, \quad $y'=\dfrac{20 x^2-171 x+333}{2 \sqrt{x^2-11 x+30}}$. \hfill Answer. $x=3.$ \item $y = (5 x-2)\cdot \sqrt{x^2+9 x+20}$, \quad $y'=\dfrac{20 x^2+131 x+182}{2 \sqrt{x^2+9 x+20}}$. \hfill Answer. $x=-2.$ \item $y = (5 x-2)\cdot \sqrt{x^2-9 x+18}$, \quad $y'=\dfrac{20 x^2-139 x+198}{2 \sqrt{x^2-9 x+18}}$. \hfill Answer. $x=2.$ \item $y = (5 x+2)\cdot \sqrt{x^2-9 x+20}$, \quad $y'=\dfrac{20 x^2-131 x+182}{2 \sqrt{x^2-9 x+20}}$. \hfill Answer. $x=2.$ \item $y = (5 x+3)\cdot \sqrt{x^2-7 x+10}$, \quad $y'=\dfrac{20 x^2-99 x+79}{2 \sqrt{x^2-7 x+10}}$. \hfill Answer. $x=1.$ \item $y = (5 x+4)\cdot \sqrt{x^2-12 x+20}$, \quad $y'=\dfrac{2 \left(5 x^2-43 x+38\right)}{\sqrt{x^2-12 x+20}}$. \hfill Answer. $x=1.$ \item $y = (5 x+4)\cdot \sqrt{x^2-18 x+80}$, \quad $y'=\dfrac{10 x^2-131 x+364}{\sqrt{x^2-18 x+80}}$. \hfill Answer. $x=4.$ \item $y = (5 x+5)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{5 \left(2 x^2-17 x+26\right)}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=2.$ \item $y = (5 x+5)\cdot \sqrt{x^2-15 x+54}$, \quad $y'=\dfrac{5 \left(4 x^2-43 x+93\right)}{2 \sqrt{x^2-15 x+54}}$. \hfill Answer. $x=3.$ \item $y = (5 x+6)\cdot \sqrt{x^2-14 x+40}$, \quad $y'=\dfrac{10 x^2-99 x+158}{\sqrt{x^2-14 x+40}}$. \hfill Answer. $x=2.$ \item $y = (5 x+6)\cdot \sqrt{x^2-16 x+60}$, \quad $y'=\dfrac{2 \left(5 x^2-57 x+126\right)}{\sqrt{x^2-16 x+60}}$. \hfill Answer. $x=3.$ \item $y = (5 x+7)\cdot \sqrt{x^2-7 x+12}$, \quad $y'=\dfrac{20 x^2-91 x+71}{2 \sqrt{x^2-7 x+12}}$. \hfill Answer. $x=1.$ \item $y = (5 x+8)\cdot \sqrt{x^2-5 x+4}$, \quad $y'=\dfrac{x (20 x-59)}{2 \sqrt{x^2-5 x+4}}$. \hfill Answer. $x=0.$ \item $y = (5 x+9)\cdot \sqrt{x^2-10 x+9}$, \quad $y'=\dfrac{2 x (5 x-33)}{\sqrt{x^2-10 x+9}}$. \hfill Answer. $x=0.$ \item $y = (5 x+9)\cdot \sqrt{x^2-16 x+63}$, \quad $y'=\dfrac{10 x^2-111 x+243}{\sqrt{x^2-16 x+63}}$. \hfill Answer. $x=3.$ \item $y = (5 x+10)\cdot \sqrt{x^2-10 x+21}$, \quad $y'=\dfrac{5 \left(2 x^2-13 x+11\right)}{\sqrt{x^2-10 x+21}}$. \hfill Answer. $x=1.$ \item $y = (5 x+10)\cdot \sqrt{x^2-13 x+40}$, \quad $y'=\dfrac{5 \left(4 x^2-35 x+54\right)}{2 \sqrt{x^2-13 x+40}}$. \hfill Answer. $x=2.$ \item $y = (6 x-4)\cdot \sqrt{x^2-7 x+12}$, \quad $y'=\dfrac{12 x^2-67 x+86}{\sqrt{x^2-7 x+12}}$. \hfill Answer. $x=2.$ \item $y = (6 x-3)\cdot \sqrt{x^2+6 x+8}$, \quad $y'=\dfrac{3 \left(4 x^2+17 x+13\right)}{\sqrt{x^2+6 x+8}}$. \hfill Answer. $x=-1.$ \item $y = (6 x-3)\cdot \sqrt{x^2-8 x+15}$, \quad $y'=\dfrac{3 \left(4 x^2-25 x+34\right)}{\sqrt{x^2-8 x+15}}$. \hfill Answer. $x=2.$ \item $y = (6 x-2)\cdot \sqrt{x^2+5 x+6}$, \quad $y'=\dfrac{12 x^2+43 x+31}{\sqrt{x^2+5 x+6}}$. \hfill Answer. $x=-1.$ \item $y = (6 x-2)\cdot \sqrt{x^2-10 x+21}$, \quad $y'=\dfrac{4 \left(3 x^2-23 x+34\right)}{\sqrt{x^2-10 x+21}}$. \hfill Answer. $x=2.$ \item $y = (6 x-2)\cdot \sqrt{x^2-12 x+35}$, \quad $y'=\dfrac{2 \left(6 x^2-55 x+111\right)}{\sqrt{x^2-12 x+35}}$. \hfill Answer. $x=3.$ \item $y = (6 x+2)\cdot \sqrt{x^2-5 x+6}$, \quad $y'=\dfrac{12 x^2-43 x+31}{\sqrt{x^2-5 x+6}}$. \hfill Answer. $x=1.$ \item $y = (6 x+3)\cdot \sqrt{x^2+8 x+15}$, \quad $y'=\dfrac{3 \left(4 x^2+25 x+34\right)}{\sqrt{x^2+8 x+15}}$. \hfill Answer. $x=-2.$ \item $y = (6 x+3)\cdot \sqrt{x^2-6 x+8}$, \quad $y'=\dfrac{3 \left(4 x^2-17 x+13\right)}{\sqrt{x^2-6 x+8}}$. \hfill Answer. $x=1.$ \item $y = (6 x+4)\cdot \sqrt{x^2+7 x+12}$, \quad $y'=\dfrac{12 x^2+67 x+86}{\sqrt{x^2+7 x+12}}$. \hfill Answer. $x=-2.$ \item $y = (6 x+4)\cdot \sqrt{x^2-8 x+12}$, \quad $y'=\dfrac{4 \left(3 x^2-17 x+14\right)}{\sqrt{x^2-8 x+12}}$. \hfill Answer. $x=1.$ \item $y = (6 x+4)\cdot \sqrt{x^2-10 x+24}$, \quad $y'=\dfrac{2 \left(6 x^2-43 x+62\right)}{\sqrt{x^2-10 x+24}}$. \hfill Answer. $x=2.$ \item $y = (6 x+6)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{6 \left(2 x^2-17 x+26\right)}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=2.$ \item $y = (6 x+6)\cdot \sqrt{x^2-15 x+54}$, \quad $y'=\dfrac{3 \left(4 x^2-43 x+93\right)}{\sqrt{x^2-15 x+54}}$. \hfill Answer. $x=3.$ \item $y = (6 x+8)\cdot \sqrt{x^2-3 x+2}$, \quad $y'=\dfrac{x (12 x-19)}{\sqrt{x^2-3 x+2}}$. \hfill Answer. $x=0.$ \item $y = (6 x+9)\cdot \sqrt{x^2-4 x+3}$, \quad $y'=\dfrac{3 x (4 x-9)}{\sqrt{x^2-4 x+3}}$. \hfill Answer. $x=0.$ \item $y = (6 x+10)\cdot \sqrt{x^2+9 x+20}$, \quad $y'=\dfrac{12 x^2+91 x+165}{\sqrt{x^2+9 x+20}}$. \hfill Answer. $x=-3.$ \item $y = (6 x+10)\cdot \sqrt{x^2-6 x+5}$, \quad $y'=\dfrac{4 x (3 x-11)}{\sqrt{x^2-6 x+5}}$. \hfill Answer. $x=0.$ \item $y = (6 x+10)\cdot \sqrt{x^2-8 x+15}$, \quad $y'=\dfrac{2 \left(6 x^2-31 x+25\right)}{\sqrt{x^2-8 x+15}}$. \hfill Answer. $x=1.$ \item $y = (7 x-4)\cdot \sqrt{x^2-15 x+56}$, \quad $y'=\dfrac{28 x^2-323 x+844}{2 \sqrt{x^2-15 x+56}}$. \hfill Answer. $x=4.$ \item $y = (7 x-2)\cdot \sqrt{x^2-11 x+24}$, \quad $y'=\dfrac{28 x^2-235 x+358}{2 \sqrt{x^2-11 x+24}}$. \hfill Answer. $x=2.$ \item $y = (7 x-1)\cdot \sqrt{x^2-13 x+40}$, \quad $y'=\dfrac{28 x^2-275 x+573}{2 \sqrt{x^2-13 x+40}}$. \hfill Answer. $x=3.$ \item $y = (7 x+3)\cdot \sqrt{x^2-13 x+42}$, \quad $y'=\dfrac{28 x^2-267 x+549}{2 \sqrt{x^2-13 x+42}}$. \hfill Answer. $x=3.$ \item $y = (7 x+5)\cdot \sqrt{x^2-9 x+14}$, \quad $y'=\dfrac{28 x^2-179 x+151}{2 \sqrt{x^2-9 x+14}}$. \hfill Answer. $x=1.$ \item $y = (7 x+6)\cdot \sqrt{x^2-11 x+28}$, \quad $y'=\dfrac{28 x^2-219 x+326}{2 \sqrt{x^2-11 x+28}}$. \hfill Answer. $x=2.$ \item $y = (7 x+7)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{7 \left(2 x^2-17 x+26\right)}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=2.$ \item $y = (7 x+7)\cdot \sqrt{x^2-15 x+54}$, \quad $y'=\dfrac{7 \left(4 x^2-43 x+93\right)}{2 \sqrt{x^2-15 x+54}}$. \hfill Answer. $x=3.$ \item $y = (7 x+10)\cdot \sqrt{x^2-11 x+30}$, \quad $y'=\dfrac{28 x^2-211 x+310}{2 \sqrt{x^2-11 x+30}}$. \hfill Answer. $x=2.$ \item $y = (8 x-4)\cdot \sqrt{x^2+6 x+8}$, \quad $y'=\dfrac{4 \left(4 x^2+17 x+13\right)}{\sqrt{x^2+6 x+8}}$. \hfill Answer. $x=-1.$ \item $y = (8 x-4)\cdot \sqrt{x^2-8 x+15}$, \quad $y'=\dfrac{4 \left(4 x^2-25 x+34\right)}{\sqrt{x^2-8 x+15}}$. \hfill Answer. $x=2.$ \item $y = (8 x-2)\cdot \sqrt{x^2-12 x+27}$, \quad $y'=\dfrac{2 \left(8 x^2-73 x+114\right)}{\sqrt{x^2-12 x+27}}$. \hfill Answer. $x=2.$ \item $y = (8 x-2)\cdot \sqrt{x^2-16 x+63}$, \quad $y'=\dfrac{2 \left(8 x^2-97 x+260\right)}{\sqrt{x^2-16 x+63}}$. \hfill Answer. $x=4.$ \item $y = (8 x+4)\cdot \sqrt{x^2+8 x+15}$, \quad $y'=\dfrac{4 \left(4 x^2+25 x+34\right)}{\sqrt{x^2+8 x+15}}$. \hfill Answer. $x=-2.$ \item $y = (8 x+4)\cdot \sqrt{x^2-6 x+8}$, \quad $y'=\dfrac{4 \left(4 x^2-17 x+13\right)}{\sqrt{x^2-6 x+8}}$. \hfill Answer. $x=1.$ \item $y = (8 x+6)\cdot \sqrt{x^2-10 x+16}$, \quad $y'=\dfrac{2 \left(8 x^2-57 x+49\right)}{\sqrt{x^2-10 x+16}}$. \hfill Answer. $x=1.$ \item $y = (8 x+6)\cdot \sqrt{x^2-14 x+48}$, \quad $y'=\dfrac{2 \left(8 x^2-81 x+171\right)}{\sqrt{x^2-14 x+48}}$. \hfill Answer. $x=3.$ \item $y = (8 x+8)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{8 \left(2 x^2-17 x+26\right)}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=2.$ \item $y = (8 x+8)\cdot \sqrt{x^2-15 x+54}$, \quad $y'=\dfrac{4 \left(4 x^2-43 x+93\right)}{\sqrt{x^2-15 x+54}}$. \hfill Answer. $x=3.$ \item $y = (9 x-5)\cdot \sqrt{x^2-19 x+90}$, \quad $y'=\dfrac{36 x^2-523 x+1715}{2 \sqrt{x^2-19 x+90}}$. \hfill Answer. $x=5.$ \item $y = (9 x-3)\cdot \sqrt{x^2+5 x+6}$, \quad $y'=\dfrac{3 \left(12 x^2+43 x+31\right)}{2 \sqrt{x^2+5 x+6}}$. \hfill Answer. $x=-1.$ \item $y = (9 x-3)\cdot \sqrt{x^2-10 x+21}$, \quad $y'=\dfrac{6 \left(3 x^2-23 x+34\right)}{\sqrt{x^2-10 x+21}}$. \hfill Answer. $x=2.$ \item $y = (9 x-3)\cdot \sqrt{x^2-12 x+35}$, \quad $y'=\dfrac{3 \left(6 x^2-55 x+111\right)}{\sqrt{x^2-12 x+35}}$. \hfill Answer. $x=3.$ \item $y = (9 x-2)\cdot \sqrt{x^2-13 x+30}$, \quad $y'=\dfrac{36 x^2-355 x+566}{2 \sqrt{x^2-13 x+30}}$. \hfill Answer. $x=2.$ \item $y = (9 x+1)\cdot \sqrt{x^2-15 x+50}$, \quad $y'=\dfrac{36 x^2-403 x+885}{2 \sqrt{x^2-15 x+50}}$. \hfill Answer. $x=3.$ \item $y = (9 x+3)\cdot \sqrt{x^2-5 x+6}$, \quad $y'=\dfrac{3 \left(12 x^2-43 x+31\right)}{2 \sqrt{x^2-5 x+6}}$. \hfill Answer. $x=1.$ \item $y = (9 x+4)\cdot \sqrt{x^2-17 x+72}$, \quad $y'=\dfrac{36 x^2-451 x+1228}{2 \sqrt{x^2-17 x+72}}$. \hfill Answer. $x=4.$ \item $y = (9 x+6)\cdot \sqrt{x^2+7 x+12}$, \quad $y'=\dfrac{3 \left(12 x^2+67 x+86\right)}{2 \sqrt{x^2+7 x+12}}$. \hfill Answer. $x=-2.$ \item $y = (9 x+6)\cdot \sqrt{x^2-8 x+12}$, \quad $y'=\dfrac{6 \left(3 x^2-17 x+14\right)}{\sqrt{x^2-8 x+12}}$. \hfill Answer. $x=1.$ \item $y = (9 x+6)\cdot \sqrt{x^2-10 x+24}$, \quad $y'=\dfrac{3 \left(6 x^2-43 x+62\right)}{\sqrt{x^2-10 x+24}}$. \hfill Answer. $x=2.$ \item $y = (9 x+7)\cdot \sqrt{x^2-11 x+18}$, \quad $y'=\dfrac{36 x^2-283 x+247}{2 \sqrt{x^2-11 x+18}}$. \hfill Answer. $x=1.$ \item $y = (9 x+9)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{9 \left(2 x^2-17 x+26\right)}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=2.$ \item $y = (9 x+9)\cdot \sqrt{x^2-15 x+54}$, \quad $y'=\dfrac{9 \left(4 x^2-43 x+93\right)}{2 \sqrt{x^2-15 x+54}}$. \hfill Answer. $x=3.$ \item $y = (9 x+10)\cdot \sqrt{x^2-13 x+36}$, \quad $y'=\dfrac{36 x^2-331 x+518}{2 \sqrt{x^2-13 x+36}}$. \hfill Answer. $x=2.$ \item $y = (10 x-5)\cdot \sqrt{x^2+6 x+8}$, \quad $y'=\dfrac{5 \left(4 x^2+17 x+13\right)}{\sqrt{x^2+6 x+8}}$. \hfill Answer. $x=-1.$ \item $y = (10 x-5)\cdot \sqrt{x^2-8 x+15}$, \quad $y'=\dfrac{5 \left(4 x^2-25 x+34\right)}{\sqrt{x^2-8 x+15}}$. \hfill Answer. $x=2.$ \item $y = (10 x-4)\cdot \sqrt{x^2+9 x+20}$, \quad $y'=\dfrac{20 x^2+131 x+182}{\sqrt{x^2+9 x+20}}$. \hfill Answer. $x=-2.$ \item $y = (10 x-4)\cdot \sqrt{x^2-9 x+18}$, \quad $y'=\dfrac{20 x^2-139 x+198}{\sqrt{x^2-9 x+18}}$. \hfill Answer. $x=2.$ \item $y = (10 x+4)\cdot \sqrt{x^2-9 x+20}$, \quad $y'=\dfrac{20 x^2-131 x+182}{\sqrt{x^2-9 x+20}}$. \hfill Answer. $x=2.$ \item $y = (10 x+5)\cdot \sqrt{x^2+8 x+15}$, \quad $y'=\dfrac{5 \left(4 x^2+25 x+34\right)}{\sqrt{x^2+8 x+15}}$. \hfill Answer. $x=-2.$ \item $y = (10 x+5)\cdot \sqrt{x^2-6 x+8}$, \quad $y'=\dfrac{5 \left(4 x^2-17 x+13\right)}{\sqrt{x^2-6 x+8}}$. \hfill Answer. $x=1.$ \item $y = (10 x+6)\cdot \sqrt{x^2-7 x+10}$, \quad $y'=\dfrac{20 x^2-99 x+79}{\sqrt{x^2-7 x+10}}$. \hfill Answer. $x=1.$ \item $y = (10 x+8)\cdot \sqrt{x^2-12 x+20}$, \quad $y'=\dfrac{4 \left(5 x^2-43 x+38\right)}{\sqrt{x^2-12 x+20}}$. \hfill Answer. $x=1.$ \item $y = (10 x+8)\cdot \sqrt{x^2-18 x+80}$, \quad $y'=\dfrac{20 x^2-262 x+728}{\sqrt{x^2-18 x+80}}$. \hfill Answer. $x=4.$ \item $y = (10 x+10)\cdot \sqrt{x^2-12 x+32}$, \quad $y'=\dfrac{10 \left(2 x^2-17 x+26\right)}{\sqrt{x^2-12 x+32}}$. \hfill Answer. $x=2.$ \item $y = (10 x+10)\cdot \sqrt{x^2-15 x+54}$, \quad $y'=\dfrac{5 \left(4 x^2-43 x+93\right)}{\sqrt{x^2-15 x+54}}$. \hfill Answer. $x=3.$
\end{enumerate}
\end{document} 

Now I want to align derivative. I tried

\documentclass{article}
\usepackage{amsmath}
\usepackage{longtable}
\usepackage{booktabs}
\begin{document}
\begin{longtable}{p{0.5cm}p{5cm}p{5cm}p{3cm}}
\toprule
Oder& The function    & Derivative of the function    & Solution of Derivative \\
\midrule
1&$y = (10 x+10)\cdot \sqrt{x^2-15 x+54}$ & $y'=\dfrac{5 \left(4 x^2-43 x+93\right)}{\sqrt{x^2-15 x+54}}$. & $x=3.$ \\
2&$y = (10 x+10)\cdot \sqrt{x^2-15 x+54}$ & $y'=\dfrac{5 \left(4 x^2-43 x+93\right)}{\sqrt{x^2-15 x+54}}$. & $x=3.$ \\
3& $y = (10 x+10)\cdot \sqrt{x^2-15 x+54}$ & $y'=\dfrac{5 \left(4 x^2-43 x+93\right)}{\sqrt{x^2-15 x+54}}$. & $x=3.$ \\
4& $y = (10 x+8)\cdot \sqrt{x^2-18 x+80}$. & $y'=\dfrac{20 x^2-262 x+728}{\sqrt{x^2-18 x+80}}$& $x=4.$\\
\bottomrule

\end{longtable}
\end{document}

How can I align this enumerate?

Answer 1

You need to make the table fit inside the textblock. Some suggestions/observations:

• There seems to be no need for fixed-width columns. Use c instead.

• Move repeated pieces of information -- y=, y'=, and x= -- out of the body of the text and into the header.

• Omit all punctuation marks and \cdot directives. Doing so will help declutter the appearance of the table.

• Insert a bit more space between the rows, say, via \addlinespace instructions.

---

\documentclass{article}
\usepackage{amsmath,longtable,booktabs,array}
\newcolumntype{C}{>{$}c<{$}} % automatic-mathmode version of "c"
\begin{document}
\begin{longtable}{@{}lCCC@{}}
\toprule
Order& \text{Function $y$} & \text{Derivative $y'$} & \text{Solution $x$} \\
\midrule
1 & (10 x+10) \sqrt{x^2-15 x+54} & \dfrac{5 (4 x^2-43 x+93)}{\sqrt{x^2-15 x+54}} & 3 \\ 
\addlinespace
2 & (10 x+10) \sqrt{x^2-15 x+54} & \dfrac{5 (4 x^2-43 x+93)}{\sqrt{x^2-15 x+54}} & 3 \\ 
\addlinespace
3 & (10 x+10) \sqrt{x^2-15 x+54} & \dfrac{5 (4 x^2-43 x+93)}{\sqrt{x^2-15 x+54}} & 3 \\ 
\addlinespace
4 & (10 x+8) \sqrt{x^2-18 x+80}  & \dfrac{20 x^2-262 x+728}{\sqrt{x^2-18 x+80}}  & 4 \\
\bottomrule

\end{longtable}
\end{document} 

---

Addendum: Here's a version of the longtable which (a) automatically inserts the row number in the first column and (b) provides more structure via \endfirsthead, \endhead, \endfoot, and \endlastfoot instructions. (Of course, the \endfoot and \endhead instructions don't come into play in the example code shown below, as the entire table fits on a single page.)

\documentclass{article}
\usepackage{amsmath,longtable,booktabs,array,etoolbox}
\newcolumntype{C}{>{$\displaystyle}c<{$}} % automatic math mode version of "c"
\newcounter{rownum}
\newcolumntype{N}{>{\stepcounter{rownum}\therownum}l}
\AtBeginEnvironment{longtable}{\setcounter{rownum}{0}}
\begin{document}

\begin{longtable}{@{} N CCC @{}}
%% Header information, first page
\toprule
\multicolumn{1}{@{}l}{Order}& \text{Function $y(x)$} & \text{Derivative $y'(x)$} & \text{Value of $x$ for} \\
\multicolumn{1}{@{}l}{} & & & \text{which $y'=0$} \\
\midrule
\endfirsthead

%% Header information, all pages but first
\multicolumn{4}{@{}l}{\footnotesize\em(continued from previous page)}\\
\midrule[\heavyrulewidth]
\multicolumn{1}{@{}l}{Order}& \text{Function $y(x)$} & \text{Derivative $y'(x)$} & \text{Value of $x$ for} \\
\multicolumn{1}{@{}l}{} & & & \text{which $y'=0$}\\
\midrule
\endhead

%% Footer information, all pages but final page
\midrule[\heavyrulewidth]
\multicolumn{4}{r@{}}{\footnotesize\em(continued on following page)}\\
\endfoot

%% Footer information, final page
\bottomrule
\endlastfoot

%% Body of longtable
& (10 x+10) \sqrt{x^2-15 x+54} & \frac{5 (4 x^2-43 x+93)}{\sqrt{x^2-15 x+54}} & 3 \\ 
\addlinespace
& (10 x+10) \sqrt{x^2-15 x+54} & \frac{5 (4 x^2-43 x+93)}{\sqrt{x^2-15 x+54}} & 3 \\ 
\addlinespace
& (10 x+10) \sqrt{x^2-15 x+54} & \frac{5 (4 x^2-43 x+93)}{\sqrt{x^2-15 x+54}} & 3 \\ 
\addlinespace
& (10 x+8) \sqrt{x^2-18 x+80}  & \frac{20 x^2-262 x+728}{\sqrt{x^2-18 x+80}}  & 4\\
\end{longtable}

\end{document} 

Answer 2

An variation of Mico answer:

\documentclass{article}
\usepackage{amsmath}
\usepackage{array,booktabs,makecell,longtable}

\newcommand\mc[1]{\multicolumn{1}{c}{\text{#1}}}
\newcounter{order}
\newcommand{\order}{\stepcounter{order}\theorder}

\usepackage{showframe}
\renewcommand*\ShowFrameColor{\color{red}}

\begin{document}
{% <-- for limiting \setcellgapes{3pt}\makegapedcells to this table only   
    \setcellgapes{3pt}
    \makegapedcells
\begin{longtable}{>{\order}c
                *{3}{>{$}l<{$}}
                  }
    \toprule
\mc{Oder}
    &    \mc{Function}    
            &   \mc{Derivative}    
                &   \mc{Solution}  \\

\midrule
   &   y = (10 x+10) \sqrt{x^2-15 x+54}
        &   y'=\dfrac{5 \left(4 x^2-43 x+93\right)}{\sqrt{x^2-15 x+54}} 
            &   x=3                             \\
   &   y = (10 x+10) \sqrt{x^2-15 x+54}
        &   y'=\dfrac{5 \left(4 x^2-43 x+93\right)}{\sqrt{x^2-15 x+54}} 
            &   x=3                             \\
   &   y = (10 x+10) \sqrt{x^2-15 x+54}
        &   y'=\dfrac{5 \left(4 x^2-43 x+93\right)}{\sqrt{x^2-15 x+54}} 
            &   x=3                             \\
   &   y = (10 x+8) \sqrt{x^2-18 x+80} 
        &   y'=\dfrac{20 x^2-262 x+728}{\sqrt{x^2-18 x+80}}
            &   x=4                             \\
    \bottomrule
\end{longtable}
}
\end{document}

For more space I used macros \setcellgapes{3pt} \makegapedcells from \makecells package, for numbering of equation serve macro order. Others is equal as at Mivo answer.