c) \( \frac{z^{7}}{z^{4}}= \)

To simplify \( \frac{z^{7}}{z^{4}} \), you can use the property of exponents that states \( \frac{a^m}{a^n} = a^{m-n} \). So, we subtract the exponents: \[ \frac{z^{7}}{z^{4}} = z^{7-4} = z^{3}. \] And there you have it! The simplified form is \( z^{3} \). Now, keep in mind that this simplification assumes \( z \neq 0 \), as division by zero is undefined in mathematics!