P = 32 A = 60
P = 2(W + L) = 32 A = W x L = 60
W + L = 32 / 2
W + L = 16
We need solve one of the variables
W + L = 32 W x L = 60
(W + L) - L = 16 - L W = 60 / L
W = 16 - L
We have 2 different expressions that both equal W
16 - L = 60 / L
16 - L - (16 - L) = 60 / L - (16 - L)
60 / L - (16 - L) = 0
Multiply both sides by L to get rid of fraction
L (60 / L - 16 + L) = 0L W = 60 / L
60 - 16L + L ^ 2 = 0 W = 60 / 8 = 7.5
L ^ 2 - 16L + 60 = 0 W = 7.5
L = (L - 8)x(L - 8)
L = 8
