The area of a rectangle is 21m squared, and the length of the rectangle is 1m less than twice the width. Find the dimensions of the rectangle.

Question

I appreciate any help you are willing to give, I'm just not the most gifted when it comes to math.

Answer 1

w(2w - 1) = 21

2w² - w = 21

2w² - w - 21 = 0

2w² + 6w - 7w - 21 = 0

2w(w + 3) - 7(w + 3) = 0

(2w - 7)(w + 3) = 0

w + 3 = 0

w = -3

Well, we can't have a side that is -3m long, so this is out.

2w - 7 = 0

2w = 7

w = 7/2

2(7/2) - 1 = 7 - 1 = 6

6 x 3 1/2