Given f(x)=1x+11\displaystyle {f{{\left({x}\right)}}}=\frac{{1}}{{{x}+{11}}}, find the average rate of change of f(x)\displaystyle {f{{\left({x}\right)}}} on the interval [10,10+h]\displaystyle {\left[{10},{10}+{h}\right]}. Your answer will be an expression involving h\displaystyle {h}.