Question

The width of a rectangle is 5ft. less than the length. The area of the rectangle is 300 ft ^2. Find the length and width of the rectangle.

Answer 1

w = L - 5 (first sentence)
L*w = 300 (formula for area of a rectangle)

substitute in first sentence says what w = so put that in the second

L(L - 5) = 300
L^2 - 5L = 300
L^2 - 5L - 300 = 0
(L - 20)(L + 15) = 0
L = 20 or L = -15
Because Length must be positive.. L = 20

W = L - 5
W = 20 - 5
W = 15