Given the function f(x)= (x-2) / (x-5), determine an interval and a point where the ave. R.O.C and the instantaneous R.O.C are equal.

IROC = [ f(x+h) - f(x) ] /h

AROC = f(x2) - f(x1) / x2 - x1

I know that in order to satisfy this, the x's must satisfy both equations when using the AROC and IROC formulas.

I'm not sure where to start, though.

I could do guess and check, but I need help for an algebraic method.