SOLUTION: The length of a rectangle is 7 meters less than twice the width. Find the dimensions if the area is 60 square me

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Question 1129247: The length of a rectangle is 7 meters less than twice the width. Find the dimensions if
the area is 60 square meters
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
length: L
width:W
if the length of a rectangle is 7 meters less than twice+ the width, we have
L=2W-7............eq.1

if the area is +60 square meters, we have
L%2AW=60......eq.2 ....substitute L
%282W-7%29%2AW=60
2W%5E2-7W=60
2W%5E2-7W-60=0
2W%5E2-15W%2B8W-60=0
%282W%5E2%2B8W%29-%2815W%2B60%29=0
2W%28W%2B4%29-15%28W%2B4%29=0
%28W+%2B+4%29+%282W+-+15%29+=+0
since width, we need only positive solution
%282+W+-+15%29+=+0=>W=15%2F2 =>W=7.5

L=2W-7............eq.1
L=2%2A7.5-7
L=15-7
L=8