Question

已知(x^3-2x^2+ax+2)/(x^2-4x+1)=x+2,求a的值.

Answer 1

(x^3-2x^2+ax+2)/(x^2-4x+1)=x+2

x^3-2x^2+ax+2=(x+2)(x^2-4x+1)

x^3-2x^2+ax+2=x^3-4x^2+x+2x^2-8x+2

x^3-2x^2+ax+2=x^3-2x^2-7x+2

对照系数知

a=-7