Kim is installing a skylight to conserve energy. She wants the width 50 cm less than the length and a total area of 15,000 cm^2. What are the dimensions?

Answer 1

w = l - 50

A = lw

l(l - 50) = 15,000

l2 - 50l - 15,000 = 0

(l - 150)(l + 100) = 0

l - 150 = 0

l = 150 cm

l + 100 = 0

l = -100

Since we don't measure using negative numbers, we disregard this solution.

w = l - 50

w = 150 - 50

w = 100 cm