The length of a rectangle is 4 inches less than twice its width. If the area of the rectangle is 70 square inches, what are its demensions
Accepted Solution
A:
By definition, the area of a rectangle is given by: A = w * l Where, w: width l: long Substituting values we have: 70 = w * (2w-4) Rewriting we have: 70 = 2w ^ 2-4w 2w ^ 2 - 4w - 70 = 0 Solving the polynomial we have: w1 = -5 w2 = 7 We take the positive root because it is a dimension. w = 7 inches Then, the length will be: l = 2w-4 l = 2 (7) -4 l = 14-4 l = 10 inches Answer: its demensions are: w = 7 inches l = 10 inches