x^3-5x^2+6x
=x(x^2-5x+6)
=x(x-2)(x-3)
4m^3+m-1
=4m^3-2m^2+2m^2-m+2m-1
=2m^2(2m-1)+m(2m-1)+(2m-1)
=(2m^2+m+1)(2m-1)
4-x^2-2xy-y^2
=4-(x+y)^2
=(2+x+y)(2-x-y)