Question

The length of a rectangle is 3 inches longer then twice its width, where w is the width of the rectangle the area of the rectangle is 90 square inches. Write an equation that represents the area and find the width and length of the rectangle.

Answer 1

A = w(2w + 3)
90 = 2w^2 + 3w
2w^2 +3w - 90 = 0
(w-6)(2w+15) = 0        (TRINOMIAL FACTORING)
w = 6 inch                   ( it can't be -15/2 because lengths can't be negative)
l = 2w + 3
  = 15 inch