<PRE><B>Question 70704</B>
If the sides of a square are decreased by 2cm, the area is decreased by 36 cm^2. What were the dimensions of the original square? 
:
Let x = length of the side of the original square
Then the area of the original square = x*x = x^2
:
sides decreased by 2cm is squared and equals original area - 36 sq cm
:
(x-2)^2 = x^2 - 36
:
x^2 - 4x + 4 = x^2 - 36; FOILed (x-2)*(x-2)
:
x^2 - x^2 - 4x = -36 - 4
:
-4x = -40
:
x = -40/-4
:
x = +10 cm is the side of the original square
:
:
Check:
original sq area = 10^2 = 100 sq cm
 New square area = 8^2 =   64
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The difference is 36 sq cm
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