Question

当X不等于-1和X不等于-2时,X-1/X^2+3X+2=

Answer 1

(X-1)/(X^2+3X+2)=(x-1)/(x+1)(x+2)=M/X+1 +N/X+2

=[M(x+2)+N(x+1)]/(x+1)(x+2)

即M(x+2)+N(x+1)=x-1

M+N=1

2M+N=-1

解得M=-2 ,N=3