1 2(a-3)²-(a-3)
=2(a-3)(a-3)-(a-3)
=(a-3)(2a-6-1)
=(a-3)(2a-7)
2 (6x-4y)(x+y)
3(x-y)(3m-2(x-y)
=(x-y)(3m-2x+2y)
4(a-b)²(18b-12(a-b)]
=(a-b)²(18b-12a+12b)
=(a-b)²(30b-12a)
=6(a-b)²(5b-2a)
5(m+n)(p+q-p+q)
=2q(m+n)
6a(x-a)-b(x-a)-c(x-a)
=(a-b-c)(x-a)
7a^n+a^(n+2)+a^(2n)
a^n(1+a²+a^n)