1) x^3+3x^2+3x+9=x^2(x+3)+3(x+3)=(x^2+3)(x+3)
2) x^2-xy-2x+2y=x(x-y)-2(x-y)=(x-y)(x-2)
3) m^2+mn-5m-5n=m(m+n)-5(m+n)=(m-5)(m+n)
4) a^2-ab-3a+3b=a(a-b)-3(a-b)=(a-3)(a-b)
5) 10ay-5by+2ax-bx=5y(2a-b)+x[(2a-b)=(5y+x)(2a-b)
6) 6by-15bx-4ay+10ax=3b(2y-5x)-2a(2y-5x)=(3b-2a)(2y-5x)
7) 5x^2-5ax-7a+7x=5x(x-a)+7(x-a)=(5x+7)(x-a)
8) 4x^2-4xz-3x+3z= 4x(x-z)-3(x-z)=(4x-3)(x-z)
9) 5ax-6bx-5ay+6by= 5a(x-y)-6b(x-y)=(5a-6b)(x-y)
10) 2m^2-mn+2mx-nx=2m(m+x)-n(m+x)=(2m-n)(m+x)