SOLUTION: What is the length and width of a rectangle with a perimeter of 40 feet and an area of 84 square feet?

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Question 929542: What is the length and width of a rectangle with a perimeter of 40 feet and an area of 84 square feet?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
A=L%2AW=84
P=2%28L%2BW%29=40
L%2BW=20
Substituting,
L=84%2FW
into the perimeter equation,
84%2FW%2BW=20
84%2BW%5E2=20W
W%5E2-20W%2B84=0
%28W-14%29%28W-6%29=0
Two solutions:
W-14=0
W=14
Then,
L=84%2F14
L=6
and
W-6=0
W=6
and
L=84%2F6
L=14