Answer:
-4z
Explanation:
Hi student! Let me help you out.
_____________________
Note that, -3z and -z are like terms. This means we can combine them right off the bat, which gives us
.
. -4z is our final answer.
Hope that this helped you! have a good day ahead.
Best Wishes!

◈◈-Greetings!-◆◆
___________________