Answer:
8m + 4n
Explanation:
To find the answer, you should distribute the 4 on the outside of the parentheses to each of the terms inside the parentheses, which would get: 4(2m) + 4n.
Simplify 4(2m) by multiplying, which gets 8m.
The equation is then 8m + 4n, which cannot be added together because the variables are different.