SOLUTION: The length of a rectangle is 8 cm less than twice the width. The area of the rectangle is 90 cm2. Find the length and width of the rectangle. length______cm width_______cm

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: The length of a rectangle is 8 cm less than twice the width. The area of the rectangle is 90 cm2. Find the length and width of the rectangle. length______cm width_______cm      Log On


   



Question 447982: The length of a rectangle is 8 cm less than twice the width. The area of the rectangle is 90 cm2. Find the length and width of the rectangle.
length______cm
width_______cm

Answer by jorel1380(3719) About Me  (Show Source):
You can put this solution on YOUR website!
n(2n-8)=90
2n2-8n-90=0
n2-4n-45=0
(n-9)(n+5)=9
n=9 or -5
Throwing out the negative answer, we get the length to be 10 cm., and the width to be 9 cm..