Step 1: The negative on the exponent means this thing is on the wrong side of the fraction. Since there is no fraction written, it's by default in the top of a fraction over 1.
[tex](-4)^{-3} = \dfrac{(-4)^{-3}}{1}[/tex]
So, move that to the bottom of the fraction and make sure the exponent becomes positive:
[tex]\dfrac{(-4)^{-3}}{1} =\dfrac{1}{(-4)^{3}}[/tex]
Now you have to decide what [tex](-4)^3[/tex] is.
