求（1/（1-x)-1/(1+x))/((x/x^2-1)+x)的值

x的平方/(x^2-2)=3
x^2=3x^2-6
2x^2=6
x^2=3

（1/（1-x)-1/(1+x))/((x/x^2-1)+x)
=[((1+x)-(1-x))/(1-x^2)]/[(x+x(x^2-1))/(x^2-1)]
=(2x/(1-x^2))/(x^3/(x^2-1))
=-2/x^2
=-2/3

x^2/(x^2-2)=3
x^2=3x^2-6
x^2=3

[1/（1-x)-1/(1+x)]/[x/(x^2-1)+x]
={[(1+x)-(1-x)]/(1-x^2)}/{[x-x(x^2-1)]/(x^2-1)}
=-(2x)/(x-x^3+x)
=-2x/x^3
=-2/x^2
=-2/3

x^2/(x^2-2)=3
则x^2=3
[1/(1-x)-1/(1+x)]/[x/(x^2-1)+x]
=(2x/(1-x^2)]/[x^3/(x^2-1)]
=2/x^2
=2/3

x^2/(x^2-2)=3
x^2=3
原式通分后是-2/x^2=-2/3