SOLUTION: the perimeter of a rectangle is 30 inches, and its area is 56 square inches .find the length and width?

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Question 709378: the perimeter of a rectangle is 30 inches, and its area is 56 square inches .find the length and width?
Answer by hheuler(6) About Me  (Show Source):
You can put this solution on YOUR website!
(Eq 1) P = 2L + 2W = 30
(Eq 2) A = LW = 56
From (Eq 1): L + W = 15 or L = 15 - W (Eq 3)
Substitute (Eq 3) into (Eq 2): (15 - W)W = 56 = 8(7)= (15 - 7)7 (Eq 4)
So the width is 7 by inspection of (Eq 4)and from (Eq 1), the length is 8.
QED