Question 92886: If the sides of a square are increased by 3 in, the area is increased by 39 in. What were the dimensions of the original square
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! If the sides of a square are increased by 3 in, the area is increased by 39 in. What were the dimensions of the original square
:
Side of original square = x
Area of original square = x^2
:
Side of new square = (x+3)
Area of new square = (x+3)^2
:
The problem equation:
New square area - original square area = 39 sq/in
(x+3)^2 - x^2 = 39
:
x^2 + 6x + 9 - x^2 = 39; FOILed (x+3)(x+3)
:
6x + 9 = 39; x^2's eliminated
:
6x = 39 - 9
;
x = 30/6
:
x = 5 in, the dimension of original square
:
:
Check using the area:
8^2 - 5^2 =
64 - 25 = 39
:
Did this make sense to you? Not that hard, right?
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