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$\newcommand{\highlight}[1]{{\color{magenta}{{#1}}}}\newcommand{\substitute}[1]{{\color{blue}{{#1}}}}\newcommand{\amp}{&}$

Is $-3$ a solution for $x$ in the equation $2x-3=5-(4+x)\text{?}$ Evaluating the left and right sides gives:

$2x-3$	${}={}$	$5-(4+x)$
	${}\stackrel{?}{=}{}$

So $-3$ a solution to $2x-3=5-(4+x)\text{.}$

Solution

We will substitute $x$ with $-3$ in the equation and simplify each side of the equation to determine if the statement is true or false:

$\begin{aligned} 2x-3\amp=5-(4+x)\\ 2(\substitute{-3})-3\amp\stackrel{?}{=}5-(4+(\substitute{-3}))\\ \highlight{-6}-3\amp\stackrel{?}{=} 5-(\highlight{1})\\ -9\amp\stackrel{\chi}{=}4 \end{aligned}$

Since $-9=4$ is not true, $-3$ is not a solution for $x$ in the equation $2x-3=5-(4+x)\text{.}$