(2x+5)^2
(2x+9) (2x-9)
(7p^2 - 6q) ( 3p^2 + 2q)
(5x-x^3 y)^2
(-a-4b^2)^2
(a^2 -2b)^3
(y^2-3x^2 ) (y^2+3x^2)
(3x-ax) (-3x-ax)
(m + 3)^3
(8a + 3b) (2a - 5b)
4x^2+20 xy+25y^2
(a^2 x^2-9x^2)
16 a^2 - 34ab - 15b^2
(y^4-9x^4)
25x^2-10 x^4 y+ x^6 y^2
m^3 + 9m^2 +27m + 27
(4x^2-81)
a^6 - 6a^4b+ 12a^2b^2 - 8b^3
21p^4 - 4p^2q - 12q^2
a^2+8ab^2+16b^2