(m+6)(m-6)
(8m+6)(8m-6)
(2x+10)(2x-10)
(6x+4)(6x-4)
(11x+13)(11x-13)
(7x+6)(7x-6)
49x^2 - 36
4x^2 - 100
m^2 - 36
121x^2 - 169
64m^2 - 36
36x^2 - 16
