已知(x2+2)/x(x+1)(x+2)=A/x+B/(x+1)+C/(x+2),求A,B,C的值
问题描述：
已知(x2+2)/x(x+1)(x+2)=A/x+B/(x+1)+C/(x+2),求A,B,C的值
答
(x2+2)恒等于A*(x+1)*(x+2)+B*x(x+2)+Cx*(x+1)=（A+B+C)X^2+(3A+2B+C)X+2A
2A=2 ,A=1,(3A+2B+C)=0（A+B+C)=1 B=-3,C=3