## Elementary Algebra

The formula for the perimeter of a rectangle is P = 2w + 2l Substitute 80 for P and 24 for l to obtain: 80 = 2 $\times$ w + 2 $\times$ 24 80 = 2w + 48 Subtract 48 from both sides 32 = 2w Divide both sides by 2 16 = w