Question

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

Answer 1

解

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

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

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

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

根据等式左右两边对应项系数相等得

a=-7