7/x(x+1)-6/(x+1)(x-1)+3/x(x-1)=0
两边乘x(x+1)(x-1)
7(x-1)-6x+3(x+1)=0
7x-7-6x+3x+3=0
4x=4
x=1
经检验,x=1时公分母x(x+1)(x-1)=0
是增根,舍去
方程无解