SOLUTION: A rectangle is three times as long as it is wide. If its length and width are both decreased by 2 cm, its area is decreased by 36 cm^2. Find the dimensions of the original rectangl

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A rectangle is three times as long as it is wide. If its length and width are both decreased by 2 cm, its area is decreased by 36 cm^2. Find the dimensions of the original rectangl      Log On


   

Question 1111002: A rectangle is three times as long as it is wide. If its length and width are both decreased by 2 cm, its area is decreased by 36 cm^2. Find the dimensions of the original rectangle.
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
Dimensions originally 3w and w, and area 3w^2.

Each dimension 2 cm smaller,
Dimensions 3w-2 and w-2, area (3w-2)(w-2)=3w^2-8w+4.

Area was decreased by 36 square centimeters.
3w%5E2-%283w%5E2-8w%2B4%29=36
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8w-4=36
8w=40
highlight%28w=5%29--------original width
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highlight%283w=15%29-------original length