Question

The length of a rectangular cake is 4 inches longer than the width, and the area is 192 square inches. Calculate the perimeter of the cake.

Answer 1

56 in

Explanation:

L = 4 + W

L · W = 192

(4 + W) · W = 192

W² + 4W - 192 = 0

Δ = 16 - 4 · (-192)

Δ = 16 + 768 = 784

W = (-4 + 28)/2 = 24/2 = 12 in

We don’t consider the negative solution because width can be only positive

L = 12 + 4 = 16 in

Perimeter = (16+12) · 2 = 28· 2 = 56 in