(x-1)(x+4)+6=0x²+3x+2=0(x+1)(x+2)=0x=-1或x=-2
see
(x+1)^3-6(x+1)-4=0 (x+1)^3+8 -6(x+1)-12=0 【(x+1)+2】【(x+1)2-2(x+1)+4】-6【(x+1)-2】=0 【(x+1)+2】【(x+1)2-2(x+1)+4-6】=0 (x+3)(x2+2x+1-2x-2-2)=0 (x+3)(x2-3)=0 x1=-3 x2=±√3