Log function monotone interval LG (1 + X / 1-x) monotone interval urgent!

Log function monotone interval LG (1 + X / 1-x) monotone interval urgent!

This logarithmic function is monotone increasing function, so find its monotone interval, that is, find its domain of definition: (1 + X / 1-x) > 1, and solve it,
(1+x/1-x)>1
(x/1-x)>0
It is equivalent to the system of equations x0
The interval is empty set or (0,1) by solving the equations respectively