Answer:
28z - 12y
Explanation:
Considering you have the expression 12z - 4y + 16z - 8y, you can notice automatically that there are like terms. We also know that to simplify an expression, you need to combine like terms.
First, change all signs:
12z - 4y + 16z - 8y
12z + (-4y) + 16z + (-8y)
Second, place like terms next to each other:
12z + 16z + (-4y) + (-8y)
Third, combine like terms:
28z + (-12y)
28z - 12y
Considering these terms have different variables, you cannot simplify any farther.