how do u know if variables go in numerator or denominator? how do u know where it goes?

Answer:
A variable goes as a denominator if it's index is negative.
For example:
[tex]x^{-1}y=\frac{y}{x}[/tex]The index of x is -1, this makes it a denominator.
The given expression:
[tex]x^4y^{-14}z^4=\frac{x^4z^4}{z^{14}}[/tex]