7/(x+x2)-3/(x-x2)=6/(x2-1)
两边同乘以x(x+1)(x-1),得
7(x-1)+3(x+1)=6x
7x-7+3x+3=6x
10x-6x=3-7
4x=-4
x=-1
经检验x=-1是增根,所以方程无解.