9a^3x^3y-18ax^2=9ax^2(a^2xy-2)
x^4-x^3-3x^6+8x=x(x^3-x^2-3x^5+8)
25x^2y^3z+125x^3yz^2-5x^5yz^4-30x^6yz=5x^2yz(5y^2+25xz-x^3z^3-6x^4)
a^4+5a^6-12a=a(a^3+5a^5-12)
150m^3n+120mn-60m^4n^2+30mn^3=10mn (15m^2+12-6m^3n+6n^2)
4x^2+8x-2=2(2x^2+4x+1)
a^2b^4c+abc= abc(ab^3+1)
9m^3n+18mn^2-36=9(m^3n+2mn^2-4)
