A rectangle has a length that is seven less than three times the width. If the area of the rectangle is 98 square inches, find the length and width of the rectangle.

Answer 1

w = width

l = 3*width-7

area = l*w = w * (3*w-7)

98 = 3w^2 - 7w

3w^2 - 7w = 98

3w^2 -7w - 98 = 0

use the quadratic formula w = -(-7) +/- sqrt((7-)^2 - 4(3)(-98))/2(3)

w = 7 or -14/3

only 7 is a viable solution

l = 3*w - 7 = 14