Question

Suppose that the length of a certain rectangle is two centimeters more than three times its width. If the area of the rectangle is 85 square centimeters, find its length and width

Answer 1

Answer:

width = 5 in

length = 17 in

Step-by-step explanation:

Area of a rectangle = length x width

width = w

length = 2 + 3w

85 = (w) x (2 + 3w)

85 = 2w + 3w³

this can be solved using quadratic equation

3w³ + 2w - 85 = 0

factors of 3w³ x -85 that add up to 2w are : +17 w and -15w

(3w³ - 15w) (17w - 85) = 0

3w(w - 5) 17(w - 5) 0

w = 5

or w = - 17/3

the width cannot be a negative number. the correct width is 5 in

Length = 2 x 3(5) = 17 inches