Answer:
The correct answer is B. 10x - 12y
Explanation:
To find this, we focus on just the like terms. So we break it down by the variable each time.
5x + 5x = 10x
-6y + -6y = -12y
z + -z = 0
So we put those answers all together to get 10 - 12y + 0 or just 10x - 12y