Respuesta :

I believe you would just substitute -5 for x.
So
  f(x)=3^-5
  and you would get f(x)=0.0041
which you can round to f(x)=0.004
f(x) = 3^-5 would equal 1/243x if you’re solving for X, however it would equal 1/243f if you’re solving for F!

Hope this helps :)