SOLUTION: A building in a large city has a rectangular base. The length of the base measures 60 ft less than three times the width. The perimeter of this base is 840 feet. What are the base'

Algebra ->  Human-and-algebraic-language -> SOLUTION: A building in a large city has a rectangular base. The length of the base measures 60 ft less than three times the width. The perimeter of this base is 840 feet. What are the base'      Log On


   



Question 1016667: A building in a large city has a rectangular base. The length of the base measures 60 ft less than three times the width. The perimeter of this base is 840 feet. What are the base's dimensions?
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
The perimeter in this case is:
2L+2W = 840
and the problem says that:
L = 3W-60 Substitute for L in the formula above:
2(3W-60)+2W = 840
6W-120+2W= 840 Add 120 on both sides and add W on left:
8W = 960 Divide both sides by 8
W = 120 And the length L is:
L= 3W-60; L = 120(3)-60= 300
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Check:
2(300)+2(120)= 840
600+240 = 840 We have the correct answer.
J