# How might I align the result of the sum of the following figure as represented in the second figure?

(2)-figure is represented as follows;

\documentclass[11pt,a4paper]{article}
\usepackage{amsmath}
\usepackage{array}
\usepackage{booktabs}

\begin{document}
using the detached coefficients, we have the scheme\\\\
\noindent
$\begin{array}{@{} >{{}}r @{} >{{}}r *{20}{ @{}>{{}}r<{{}}@{} } } & 1 & + & _nC_{1} & + & _nC_{2} & + & _nC_{3} & + & \dotsb & + & _nC_{n-1} & + & _nC_{n} \\ \times \\ & 1 & + & 1 & \\ \midrule & 1 & & & + & _nC_{1} & & & + & _nC_{2} & & & & & & & & + & _nC_{n} \\ & & & & + & 1 & & & + & _nC_{1} & & & & & & & & + & _nC_{n-1} & + & _nC_{n} \\ \midrule \end{array}$
\end{document}

• It looks to me that the first two lines and the bottom line are normal expressions and the two intermediate lines are aligned by hand (badly). – John Kormylo Oct 8 '15 at 15:25