## Sally 5 years ago F(x)= (x-7) ----- (2x+5) find F^-1 (x)

1. anonymous

To find the inverse switch the x and y from you original function$y=\frac{x-7}{2x+5}$ switch the x with y and find y:$x=\frac{y-7}{2y+5}\rightarrow (2y+5)x=y-7\rightarrow 2yx+5x=y-7$ $5x+7=y-2yx$ fractor out a y form the right hand side:$5x+7=(1-2x)y \rightarrow y=\frac{5x+7}{1-2x}$

2. Sally

3. anonymous

sorry I should have changed it its$f^{-1}(x)=\frac{5x+7}{1-2x}$

4. Sally

Thank you very much.