(3f-3)(3f+3)
9f^2-9
(x+3)(x-2)
x^2+x-6
(ab-bc)(ab+bc)
(a^2)(b^2)-(b^2)(c^2)
(3f-3)(f+9)
9f^2+24f-27
(7+6)(7-6)
49-36=13
(y+2)(y+2)
y^2+4y+4
(-m-4)^2
m^2+8m+16
(m-4)^2
m^2-8m+16
(x-3)(x-2)
x^2-5x+6
(m+2)(m-5)
m^2-3m-10
(y+2)(y-2)
y^2-4
(m+4)^2
m^2+8m+16
(f-2)^2
f^2-4f+4
(-y+2)(-y-2)
y^2-4
(4+5a)^2
16+40a+25a^2
(a-g)(a+g)
a^2-g^2
(m-2)(m-5)
m^2-7m+10
(5a-2)(5a+2)
25a^2-4
(3m-2)(3m-2)
9m^2-12m+4
(m+5)(m-5)
m^2-25