## Elementary Algebra

w = $\frac{P}{2}-l$
Using the properties of equality, we obtain: P = 2l + 2w $\frac{P}{2}$ = $\frac{2l}{2}$ + $\frac{2w}{2}$ Divide both sides by 2 $\frac{P}{2}$ = l + w $\frac{P}{2}$ - l = l - l + w Subtract l from both sides w = $\frac{P}{2} - l$