SOLUTION: For some reason, I keep coming up with 13 as the answer to this question The length of the rectangle is 4 times its width, the perimeter is 90y, what is the area?

Algebra ->  Rectangles -> SOLUTION: For some reason, I keep coming up with 13 as the answer to this question The length of the rectangle is 4 times its width, the perimeter is 90y, what is the area?      Log On


   

Question 343278: For some reason, I keep coming up with 13 as the answer to this question
The length of the rectangle is 4 times its width, the perimeter is 90y, what is the area?
Found 2 solutions by Fombitz, scott8148:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Your answer should have y in it in some capacity so something is off.
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The perimeter of a rectangle is,
P=2L%2B2W=90y
L%2BW=45y
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L=4W
Substitute,
4W%2BW=45y
5W=45y
W=9y
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L=4%289y%29
L=36y
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The area of a rectangle is,
A=L%2AW
A=%289y%29%2836y%29
highlight%28A=324y%5E2%29

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
"length of the rectangle is 4 times its width" ___ L = 4W

"the perimeter is 90y" ___ 2L + 2W = 90y

substituting ___ 2(4W) + 2W = 90y ___ 10W = 90y ___ W = 9y

substituting ___ L = 4(9y) ___ L = 36y

A = L * W = 36y * 9y = 324y^2