1) (x+y)(x²-xy+y²)
2) (x-y)(x²+xy+y²)
3) (m-n)(m²+mn+n²)
4) (m+n)(m-mn+n²)
5) (p+q)(p²-pq+q²)
6) (p-q)(p²+pq+q²)
7) (a+2)(a²-2a+4)
8) (a-2)(a²+2a+4)
9) (m+3)(m²-3m+9)
10) (n-3)(n²+3n+9)
11) (1-x)(1+x+x²)
12) (1+y)(1-y+y²)
