If f(x)=54x659x3\displaystyle {f{{\left({x}\right)}}}=\frac{{5}^{{-{4}{x}-{6}}}}{{5}^{{-{9}{x}-{3}}}}, find f(x)\displaystyle {f}'{\left({x}\right)}. Use exact values.

f(x)=\displaystyle {f}'{\left({x}\right)}=