Answer
D) $w=\frac{P}{2}-ℓ$
Work Step by Step
To solve for the width, $w$ needs to be isolated on its own side of the equation.
$P=2(ℓ+w)$
$P\div2=(2(ℓ+w))\div2$
$\frac{P}{2}=ℓ+w$
$\frac{P}{2}-ℓ=w$
This means that the answer is D, $w=\frac{P}{2}-ℓ$.
