the length of a rectangle is 2 centimetres less than twice the width. the area of the rectangle is 180 square centimetres. find the length and width of the rectangle.

1 answer

L W = 180
2W -L = 2

Solve for L and W
(2W -2)*W -180 = 0
2W^2 -2W -180 = 0
This is a factorabble quadratic equation.
(W^2 -W -90) = 0
(W -10)(W+9) = 0

W = 10 cm. Ignore the negative root (-9)
L = 180/W = 18