equations
I want to write the step by step solution of a system equation in LaTeX. But, dispite I can write the system equation, I don't know how to write at the right side of this system equation the steps of the solution. This is the code I used to write the system:
$\left.
\begin{array}{rcl}
\tan(\alpha) & = & \dfrac{h}{x} \\
\tan(\beta) & = & \dfrac{h}{d - x}
\end{array}
\right\}$
Thank you very much.
Instead of fixing your approach, I just show two other possibilities which I would prefer here.
% arara: pdflatex
\documentclass{article}
\usepackage{xcolor}
\usepackage{mathtools}
\usepackage{tikz-cd}
\begin{document}
\[\rightarrow x(ax-a+1)=0\rightarrow\begin{dcases}
{\color{red}x=0}\\
ax-a+1=0\rightarrow x=\frac{a-1}{a}\rightarrow{\color{red}x=1-\frac{1}{a}}
\end{dcases}\]
\[\begin{tikzcd}[%
,row sep={10,between origins}, column sep=15
,every arrow/.append style={start anchor=east, end anchor=west}
,/tikz/column 2/.append style={anchor=base west}
]
& \color{red}x=0\\
\rightarrow x(ax-a+1)=0 \arrow{ur}\arrow{dr} & \\
& ax-a+1=0\rightarrow x=\dfrac{a-1}{a}\rightarrow{\color{red}x=1-\dfrac{1}{a}}
\end{tikzcd}
\]
\end{document}
The \rightarrow in front of the big brace is not really needed, though.
If you want to separate the arrows in my second example, you can do something like \arrow[shorten <= 1mm]{ur}\arrow[shorten <= 1mm]{dr} or you add some yshift to their start anchors.
You can use nicematrix and its powerful methods.
\documentclass{article}
\usepackage{amsmath}
\usepackage{nicematrix}
\AtBeginEnvironment{NiceArray}{\tracinglostchars=0 }
\begin{document}
\[
\renewcommand{\arraystretch}{1.2}
\begin{NiceArray}{ @{} r @{} >{{}}c<{{}} @{} l l}
f(x) &=& x + 1 & \Block{2-1}{\text{whatever}}\\
g(x) &=& x + 2 \\
h(x) &=& x + 3 & \Block{3-1}{\text{something else}}\\
k(x) &=& x + 4 \\
l(x) &=& x + 5 \\
\CodeAfter
\SubMatrix.{1-3}{2-3}\}
\SubMatrix.{3-3}{5-3}\}
\end{NiceArray}
\]
\end{document}
The strange setting to \tracinglostchars is to avoid spurious warnings (but they deserve some investigation).
The specifications for the columns are the usual ones to mimic aligned, including the setting to \arraystretch. We build two “submatrices”, with empty delimiter on the left and braces on the right, plus two blocks spanning two and three rows respectively.
A couple of LaTeX runs are necessary for the output to stabilize, because ornamentations are set in successive steps after the object has been measured.
Best Answer
Something like this?
Package
amsmathprovidesalignedfor equations systems inside an equation line. Then also\dfracis not needed and\fracsuffices.There is also environment
rcasesof packagemathtools, but it is not used here, because of the additional alignment.