SOLUTION: 2. Suppose that the length of a rectangle is three cm longer than twice the width and that the perimeter of the rectangle is 90 cm. a) Set up an equation for the perimeter involv

Algebra ->  Rectangles -> SOLUTION: 2. Suppose that the length of a rectangle is three cm longer than twice the width and that the perimeter of the rectangle is 90 cm. a) Set up an equation for the perimeter involv      Log On


   

Question 339343: 2. Suppose that the length of a rectangle is three cm longer than twice the width and that the perimeter of the rectangle is 90 cm.
a) Set up an equation for the perimeter involving only W, the width of the rectangle.
Answer:
b) Solve this equation algebraically to find the length of the rectangle. Find the width as well.
Answer: Length ______, Width ______
Show your work here:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let width be w
length = 2w+3
..
Perimeter = 2*(w+2w+3)
Perimeter = 2*(3w+3)
Perimeter = 6w+6
...
6w+6=90
add -6
6w+6-6=90-6
6w=84
divide by 6
w = 84/6
w= 14 cm. width
length = 2w+3
= 2*14+3
= 31 cm length