a/(x+2)+b/(x-2)=(X+4)/(x^2-4),两边同乘以(x²-4)得:a(x-2)+b(x+2)=4+x(a+b)x-2a+2b=4+x比较伏凯系数得:a+b=1-2a+2b=4解方程组得:a=-1/缺闷唤罩颤2b=3/2
A=1.B=3