X^2-2XY+Y^2
25V^2-40VW+16Y^2
9X^2-12X+4
16X^2-32XY+16Y^2
49X^2-28XY+4Y^2
(4X-4Y)^2
(7Y-27)^2
(X-Y)^2
(5V-4W)^2
(3X-2)^2
