Answer:
[tex]z \geqslant - 15[/tex]
Step-by-step explanation:
[tex]5z \geqslant - 75 \\ \\ z \geqslant - \frac{75}{5} \\ \\ z \geqslant - 15[/tex]
z ≥ -15
divide both sides by 5 to get z alone
5z/5 ≥ -75/5