# How to align the first line in “align*” to the “item” counter

\documentclass[12pt,a4paper]{article}
\usepackage{amsmath}
counter-format={tsk[1])},%%1,a,A,r,R
label-format=\bfseries,
label-width=1.5em,
label-align=left,    %% or right as you wish
label-offset=0.5em,
item-indent=2em,
after-item-skip=0pt,
after-skip=-0.5\baselineskip,
before-skip=0.5\baselineskip,
resume=false         %% comment this for not to resume
]{problems}[\item](4)%% (4)here makes all of them in 4columns

\begin{document}

\begin{problems}(4)
\item
\begin{align*}
3x+y &= 7 \\
2x+y &= 6
\end{align*}
\item $\begin{cases} 3x+y &= 7 \\ 2x+y &= 6 \end{cases}$
\item $\begin{matrix} 3x+y &= 7 \\ 2x+y &= 6 \end{matrix}$
\end{problems}
\end{document}


How do I change this, so that $3x+y=7$ is vertically aligned with 1)?

That is, I'd like to have the first line of the simultaneous equation to be lifted.

Thank.

• see, if \item \begin{aligned} ... \end{aligned} helps. – Zarko May 31 '16 at 20:44
• instead of using align*, which is by definition a display structure, use \begin{aligned} ... \end{aligned} which is meant to be used as a component, similar to the cases and matrix. – barbara beeton May 31 '16 at 20:45
• As previous commenters have said; see Vertical alignment of align* in enumerate for an example. – Torbjørn T. May 31 '16 at 20:53
• \begin{aligned}[t] solved this! – Chen Stats Yu May 31 '16 at 20:53
• Can you complete your code to make it compilable please? – cfr May 31 '16 at 20:55

\item
\begin{aligned}[t] 2x+y &= 21 \\ x-y &= 6 \end{aligned}
\begin{aligned}[t] 5x+y &= 28 \\ x-y &= 2 \end{aligned}