[tex]-x^{-y}[/tex]
You have to know that every number to negative power is the inverse, for example:
[tex]3^{-1}=\frac{1}{3^1}[/tex]
in this exercise we will make the same thing
when [tex]x=-2~~and~~y=3[/tex]
[tex]-(-2)^{-3}[/tex]
let's do the inverse
[tex]-\frac{1}{(-2)^3}[/tex]
now [tex](-2)^3=-8[/tex]
[tex]-\frac{1}{-8}[/tex]
doing the signal rule
[tex]\boxed{\boxed{\frac{1}{8}}}[/tex]
