1) (p-q)(a-1)
2) 1+b-x(b+1)= (b+1)(1-x)
3) x(y+2)-2(y+2)= (x-2)(y+2)
4) a(x+y)-2b(x+y)= (x+y)(a-2b)
5) 11(x+y)-x(y+x)= (11-x)(x+y)
6) n(k-n)+m(k-n)= (k-n)(n+m)
7) a(x²+y²-1)-b(x²+y²-1)= (x²+y²-1)(a-b)
1) (p-q)(a-1)
2) 1+b-x(b+1)= (b+1)(1-x)
3) x(y+2)-2(y+2)= (x-2)(y+2)
4) a(x+y)-2b(x+y)= (x+y)(a-2b)
5) 11(x+y)-x(y+x)= (11-x)(x+y)
6) n(k-n)+m(k-n)= (k-n)(n+m)
7) a(x²+y²-1)-b(x²+y²-1)= (x²+y²-1)(a-b)