Answer
$l=\dfrac{P-2w}{2}$
Work Step by Step
$\bf{\text{Solution Outline:}}$
To solve the given equation, $
P=2l+2w
$ for $
l
,$ use the properties of equality to isolate the variable.
$\bf{\text{Solution Details:}}$
Using the properties of equality to isolate the variable, the equation above is equivalent to
\begin{array}{l}\require{cancel}
P=2l+2w
\\\\
P-2w=2l
\\\\
\dfrac{P-2w}{2}=\dfrac{2l}{2}
\\\\
\dfrac{P-2w}{2}=l
\\\\
l=\dfrac{P-2w}{2}
.\end{array}
