(a+2b)(a-2b)
(2m-3n)(2m+3n)
(4m-7n)(4m+7n)
(m-n)^2
(3ab+4b)^2
(3a+4b)^3
(12m+5n)^3
(5m+2n)^3
(-7mn-2n)^2
(p-q)^3
(6x-7y)^3
(2x+3y)^2
(-x-y)^3
(-m+n)^3
(x+5)(x-5)
(6ab-c)^2
(2a-7b)^3
(9p-4q)^2
(4x+5y)^2
(-3x+2y)^2
