Answer:
(5/7)m + 2n + 3
Step-by-step explanation:
Rewrite 3/7m as (3/7)m for added clarity, also 2/7m as (2/7)m.
Adding (3/7)m and (2/7)m results in (5/7)m.
Next, combine -3 and 6, which yields 3.
I expected that there'd be only one term in m in both quantities. (3/7)m - 3 + 4n does have only one term, but (2/7)m - 2m + 6) seems to have two m terms. I will assume that you actually meant (2/7)m - 2n + 6).
Combining like terms, we get (5/7)m + 3 + 4n - 2n, or
(5/7)m + 2n + 3