Question

z^(-3)/z^(-7)

how do I get rid of the negitive exponent

Answer 1

Get the inverse of it.
\[z^{(-3)}=\frac{1}{z^{3}} Likewise \frac{1}{z^{(-7)}}=z^{7}\]

Answer 2

Remember that \(\Large\frac{x^{a}}{x^{b}} = x^{a - b}\)

It doesn't matter if \(a\) and/or \(b\) are positive or negative. The standard rules of addition and subtraction apply.