# An equation with two splits / differing alignments

I would like to layout an equation in the following form:

x=5+3-4
-4+3+5
=8-8+8
=8


In words: I want to split the equation at two points; one where the first equation splits over two splits and the minus signs align, and the other where the equal signs align.

I've tried using \equation{} and \split{}, either with two separate ones or trying to nest them, but nothing appears to work! Any ideas?

I can use an \alignCenterstack here because the column alignment is rlrl. If it were other, I could always use a \tabularCenterstack.

\documentclass{article}
\usepackage{tabstackengine}
\TABstackMath
\begin{document}
\TABbinary \setstackaligngap{0pt} \alignCenterstack{ x=& 5 + 3 &-& 4\\ & &-& 4 + 3 + 5\\ & 8 - 8 &+& 8\\ =& 8 & & }
\end{document}


By default in tabstackengine, one can think of & tabs as being "replaced" with {}&, so that all cells have an empty group on the right. This helps spacing if relations and binary relations are placed at the right side of a cell and unary relations are placed at the left. In this case, however, I need the + and - to behave as binary in column 3, so \TABbinary instead "replaces" the & with {}&{}, so that all cell boundaries are padded with an empty group.

The \setstackaligngap{} sets the horizontal gap introduced after left-aligned columns of the align-stack, which here I want as 0pt.

The tabular stack equivalent is

\documentclass{article}
\usepackage{tabstackengine}
\TABstackMath
\begin{document}
$\TABbinary \setstacktabulargap{0pt} \tabularCenterstack{rll}{ x=& 5 + 3 &- 4\\ & &- 4 + 3 + 5\\ & 8 - 8 &+ 8\\ =& 8 & }$
\end{document}


You can use standard amsmath tools:

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin{split} x&=\begin{aligned}[t] 5+3&-4 \\ &-4+3+5 \end{aligned} \\ &=8-8+8 \\ &=8 \end{split}

\end{document}