SOLUTION: write an algebraic equation and use it solve the problem. problem is: Dave and Jane Wells have a new rectanglular driveway. The perimeter is 168 feet. the length is 12 feet long

Algebra ->  Equations -> SOLUTION: write an algebraic equation and use it solve the problem. problem is: Dave and Jane Wells have a new rectanglular driveway. The perimeter is 168 feet. the length is 12 feet long      Log On


   

Question 299534: write an algebraic equation and use it solve the problem.
problem is: Dave and Jane Wells have a new rectanglular driveway. The perimeter is 168 feet. the length is 12 feet longer than three times the width. What are the dimensions of the driveway. I know P=2L+2W and that for this problem L=3*W+12 but I'm confused as to how to put it together in one equation or where to go from here. Thanks.
Found 2 solutions by jim_thompson5910, stanbon:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Hint: Since "The perimeter is 168 feet", this means that P=168. Also, you found that L=3W%2B12. So plug these expressions into P=2L%2B2W to get 168=2%283W%2B12%29%2B2W. I'll let you take it from here.

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Dave and Jane Wells have a new rectanglular driveway. The perimeter is 168 feet. the length is 12 feet longer than three times the width. What are the dimensions of the driveway. I know P=2L+2W and that for this problem L=3*W+12 but I'm confused as to how to put it together in one equation or where to go from here
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Substitute and Solve:
168 = 2W + 2(3W+12)
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84 = W + 3W+12
4W = 72
W = 18
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Since L = 3W + 12,
L = 3*18+12
L = 66
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Cheers,
Stan H.
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