(x+2)(x+2)
x2+4x+4
(2x-3)(2x-3)
4x2-12x+9
(x+y)(x-y)
x2+y2
(5x2+2y)(5x2+2y)
25x4+20x2y+4y2
(5y4-8)(5y4+8)
25y8-64