P = 2W + 2L ......so
8(2x+1) = 2(3x + 4) + 2(4x + 3) simplify
16x + 8 = 6x + 8 + 8x + 6
16x + 8 = 14x + 14 subtract 14x, 8 from both sides
2x = 6 divide both sides by 2
x = 3
So...the sides are 3(3) + 4 = 9 + 4 = 13 inches and 4(3) + 3 = 12 + 3 = 15 inches
