解:$(3)$由$ \frac {A · F}{2x} = \frac {(x+1) · F(x+1)}{2x} = \frac {x · F(x+1)}{2x}+\frac {F(x+1)}{2x}$,得$F(x+1)=2x$;
由$ \frac {A · F}{2}= \frac {(1-\frac {1}{x}) · F(1-\frac {1}{x})}{2x}=\frac {F(1-\frac {1}{x})}{2x}-\frac {F(1-\frac {1}{x})}{2x²}$,得$F(1-\frac {1}{x} =2x²$,
∴原方程可化为$\frac {2x}{2x-2}-1=\frac {4}{2x²-2} $
整理,得$\frac {1}{x-l}=\frac {2}{(x-1)(x+1)}$,即$x+1=2$
解得$x=1$
经检验,$x=1$是原方程的增根
∴原方程无解