SOLUTION: the length of a rectangle is increased by 80%. By what percent must its width be decreased to keep the same area?

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Question 372581: the length of a rectangle is increased by 80%. By what percent must its width be decreased to keep the same area?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
the length of a rectangle is increased by 80%. By what percent must its width be decreased to keep the same area?
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Assume the original value for Length is 10. let W = the width
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Use 1.8 for an 80% increase in the length
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Let x = decimal equiv of percent decrease in width required for equal areas
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Original area = new area
10*W = 1.8(10)*(1-x)W
10W = 18(1-x)W
Divide both sides by W
10 = 18(1-x)
10 = 18 - 18x
18x = 18 - 10
18x = 8
x = 8%2F18
x = .4444 = 44.44% decrease in the width required
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