How to align the lines on the left

Question

Consider the code

\begin{align*}

(pq+q-3)^2-(3pq+p+q-6)(pq+q-3)+2(p^2q^2+p^2q+pq^2-7pq+p+q+2)\\
=&\;(p^2q^2+q^2+9+2pq^2-6q-6pq)

+(-3p^2q^2-p^2q-pq^2+6pq-3pq^2-pq-q^2+6q+9pq+3p+3q-18)\\+2(p^2q^2+p^2q+pq^2-7pq+p+q+2)\\

=&\;p^2q-5-6pq+5p+5q\\

=&\;pq(p-6)+5(p+q-1)\\
\end{align*}

I used the technique which was shown here How to align the equations to start from left

but I it is not working here.

The lines are getting disbalanced.Can someone help please

your equation are to long that can be fit in text width, can be broken into more lines? — Zarko, Apr 02 '19 at 05:11
align is designed to provide the correct spacing after operators when the & is placed before them. Moving the & would get rid of the need to explicitly add space. — barbara beeton, Apr 02 '19 at 15:35

score 2 · Accepted Answer · answered Apr 02 '19 at 05:07

2

First of all: remove all blank lines inside align*.

Some of your lines don't have &, which causes the equation to be unbalanced.

Fix:

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{align*} 
&\;(pq+q-3)^2-(3pq+p+q-6)(pq+q-3)+2(p^2q^2+p^2q+pq^2-7pq+p+q+2)\\ =&\;(p^2q^2+q^2+9+2pq^2-6q-6pq)+(-3p^2q^2-p^2q-pq^2+6pq-3pq^2-pq-q^2+6q\\
&\quad+9pq+3p+3q-18)+2(p^2q^2+p^2q+pq^2-7pq+p+q+2)\\ 
=&\;p^2q-5-6pq+5p+5q\\ 
=&\;pq(p-6)+5(p+q-1)\\ 
\end{align*}
\end{document}

To avoid margin exceeding, consider adding \usepackage{geometry} or change the line-breaking points.

answered Apr 02 '19 at 05:07

Yes,how does the package geometry help and how to use it,if i use it will it automatically align the lines to the left – Learnmore Apr 02 '19 at 05:20
@Learnmore article's default margin is very big and IMHO ugly, and geometry can make the margin much nicer. You can even control the margin using this package. For more information read the package documentation. – Apr 02 '19 at 05:23
How should i use it,will writing \usepackage{geometry} take care of all4 – Learnmore Apr 02 '19 at 05:31
@Learnmore It only takes care of the margin. You can set your own margin by \usepackage[margin=1in]{geometry} or \usepackage[top=1cm,bottom=2cm,left=3cm]{geometry}, etc. – Apr 02 '19 at 05:36

Zarko · Answer 2 · 2019-04-02T06:32:58.597

with use of the macro \MoveEqLeft from the package mathtools and correct placing of ampersands:

\documentclass{article}
\usepackage{geometry}
\usepackage{mathtools}

%---------------- show page layout. don't use in a real document!
\usepackage{showframe}
\renewcommand\ShowFrameLinethickness{0.15pt}
\renewcommand*\ShowFrameColor{\color{red}}
%---------------------------------------------------------------%

\begin{document}

\begin{align*}
\MoveEqLeft
(pq+q-3)^2-(3pq+p+q-6)(pq+q-3)+2(p^2q^2+p^2q+pq^2-7pq+p+q+2)    \\
& = (p^2q^2+q^2+9+2pq^2-6q-6pq)                                 \\
&\quad +(-3p^2q^2-p^2q-pq^2+6pq-3pq^2-pq-q^2+6q+9pq+3p+3q-18)   \\
&\quad +2(p^2q^2+p^2q+pq^2-7pq+p+q+2)                           \\
& = p^2q-5-6pq+5p+5q                                            \\
& =  pq(p-6)+5(p+q-1)
\end{align*}
    \end{document}

How to align the lines on the left

2 Answers2