A square has a side 5 centimeters shorter than the side of a second square. The area of the larger square is four times the area of the smaller square. Find the side of each square Choose the correct choice from the following answers:	A) 5	B) 6	C) 7	D) 8	E) 9

Rationale: let x be the side of the smaller square and y be the side of the larger square . the statement ` ` a square has a side 5 centimeters shorter than the side of a second square ' ' may be formulated by x = y - 5 the area of the smaller square is equal to x 2 = ( y - 5 ) 2 and the area of the larger square is equal to y 2 the statement ` ` the area of the larger square is four times the area of the smaller square ' ' may be formulated by y 2 = 4 ( y - 5 ) 2 write the above equation so that the right side is equal to 0 y 2 - 4 ( y - 5 ) 2 = 0 the left side is made up of the difference of two squares and can be easily factored as follows [ y - 2 ( y - 5 ) ] [ y + 2 ( y - 5 ) ] = 0 solve for y to find y = 10 and y = 10 / 3 . we now use the equation x = y - 5 to find x y = 10 and x = 5 for the second solution y = 10 / 3 , x is negative and can not be accepted as the length of the side of a square must be positive . answer a
Answer: A