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Question 440478: A rectangle with an area pf 80cm^2 has a width that is three more than one half its length. What is the width of the rectangle?
I know that W=L1/2+3 and then I just got lost not having either the width or length.
Thank you for your help!
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! A rectangle with an area pf 80cm^2 has a width that is three more than one half its length.
What is the width of the rectangle?
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The area equation
L*W = 80
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We know that: W = (.5L+3)
Use this to replace W in the area equation
L(.5L+3) = 80
.5L^2 + 3L = 80
Get rid of that decimal, multiply by 2. results:
L^2 + 6L = 160
A quadratic equation:
L^2 + 6L - 160 = 0
This will factor to:
(L+16)(L-10) = 0
Two solutions, but we only want the positive one
L = 10 cm
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Find W, from the statement,"width that is three more than one half its length."
W = .5(10) + 3
W = 5 + 3
W = 8 cm is the width
:
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Confirm this by finding the area with these values: 10 * 8 = 80
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