Question 305939
Use x,y notation.
{{{y=(7x+5)/(2x-5)}}}

Now interchange the x's and y's and solve for y.
{{{highlight( x)=(7highlight( y)+5)/(2highlight( y)-5)}}}
{{{(2y-5)x=7y+5}}}
{{{2yx-5x=7y+5}}}
{{{2yx-7y=5+5x}}}
{{{y(2x-7)=5x+5}}}
{{{y=(5x+5)/(2x-7))}}}
{{{highlight_green(f^(-1)(x)=(5x+5)/(2x-7))}}}
This new y is the inverse of the original function.