Question

已知(x-1)(x-2)分之2x+1=x-1分之A+x-2分之B,求A²+B²的值

Answer 1

(x-1)(x-2)分之2x+1=x-1分之A+x-2分之B 两边乘（x-1）(x-2)

2x+1=A(x-2)+B(x-1)

2x+1=(A+B)X-(2A+B)

A+B=2

2A+B=-1

两式相减

A=-1-2=-3

B=2-A=2+3=5