已知(a/x-2)+(b/x+1)=3/(x+1)(x-2),求a,b
(a/x-2)+(b/x+1)=3/(x+1)(x-2), 对x={x∣x∈R，且x≠2,x≠-1}恒成立，则a(x+1)+b(x-2)=3(a+b)x=3+2b-a令x=0,x=1代入上式，得3+2b-a=03+b-2a=0解得a=1,b=-1
