Question

A garden was originally 20 ft by 23 ft. If both dimensions are decreased by the same amount, the area of the garden will be deceased by 120 ft^2. Find the dimension of the new garden.

Answer 1

20ft × 17ft

Explanation:

(20-x)(23-x) = (20×23) - 120

460 - 43x + x² = 460 - 120

x² - 43x + 120 = 0

x² - 40x - 3x + 120 = 0

x(x - 40) - 3(x - 40) = 0

(x - 40)(x - 3) = 0

x = 3, 40

x = 3

New dimensions:

(23-3) × (20-3)

20 × 17