Question

x^-4*4

Answer 1

What you have written can be simplified to\[\frac{ 4 }{ x ^{4} }\]

Answer 2

That is, assuming you had intended to write\[x ^{-4}\times4\]

Answer 3

It may be that the intention was \[x^{-4*4}\]which is equivalent to \[(x^{-4})^4\]