Question 611078: find the length and the width of a rectangle whose perimeter is 18 ft whose area is 20 square feet
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! find the length and the width of a rectangle whose perimeter is 18 ft
2L + 2W = 18
simplify, divide by 2
L + W = 9
L = (9-W)
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whose area is 20 square feet
L*W = 20
Replace L with (9-W)
W(9-W) = 20
-W^2 + 9W - 20 = 0
Multiply by -1, easier to factor
W^2 - 9W + 20
Factors to
(W-4)(W-5) = 0
Two solutions
W = 4 ft is width, then 5 ft is the Length
and
W = 5 ft is the width, then 4 ft is the Length
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