x3-7x+6=0
x3-x-6x+6=0
x(x2-1)-6(x-1)=0
x(x+1)(x-1)-6(x-1)=0
(x-1)(x^2+x-6)=0
(x-1)(x+3)(x-2)=0
x=1或x=-3或x=2