Question 92713
 If the sides of a square are decreased by 2cm, the area is decreased by 36cm^2. What were the dimensions of the original square?
:
Let x = side of the original square
x^2 = area of the original square
:
(x-2) = side of the new square
(x-2)^2 = area of the new square
:
Original square area - new square area = 36 cm^2
  x^2 - (x-2)^2 = 36
  x^2 -(x^2 - 4x + 4) = 36
  x^2 - x^2 + 4x - 4 =  36
  4x = 36 + 4
  4x = 40
   x = 10 cm is the side of the original square
:
:
10^2 - 8^2 = 36