1. Algebra Help

Yeah, I am having problems with these 3 problems.

14. 6x^−2 y^−4 z
15. (r ^−5 )(s^4 )
16. (x^−3 y ^4 z^−2 ) ÷ (xy^2 z^−2 )

The teacher is saying, Simplify each expression. Do not use negative exponents. So, what do I do with those negatives?

Also, would it be against the rules to post the read of the questions That I have answered, so that somebody can check my work?

$\displaystyle x^{-1} = \frac{1}{x}$.