(bx-1)*(x^2－x+2)+1=bx^3-bx^2+2bx-x^2+x-2+1=bx^3-(b+1)x^2+(2b+1)x-1因为x^3－2x^2+ax－1=bx^3-(b+1)x^2+(2b+1)x-1所以b=1,a=2b+1=3a^b =3^1=3
-1 a=-1; b=1
