Question 253220: the width of a rectangle is 5 meters less than its length. the area is 84 square meters. find the dimensions of the rectangle.
Answer by richwmiller(17219)   (Show Source):
You can put this solution on YOUR website! This problem could be in word problems geometry or quadratic equations.
Area=L*W
W=L-5
substitute L-5 for W
84=L*(L-5)
84=L^2-5L
L^2-5L-84=0
we ant factors of 84 with a difference of 5
1,84
2,42=6*7=3*2*7
3,14
4,21
6,14
7,12
7 and 12 will do
We want the larger number to be negative
(L-12)(L+7)=0
L=12 since a rectangle can't have a negative size of 7
W=L-5=7
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