so I am assuming that 2m2 means 2m^2 so
we can only combine m's with m's and n's with n's
group them together (m's with m's and n's with n's)
using the propoerty that says
a+b=b+a so we can move them around so
2m^2+3m-6m^2-2m-4n^2+7n^2
we can combine m^2 and m^2's but not m^2 and m so
regroup with like powers
2m^2-6m^2+3m-2m-4n^2+7n^2
add
-4m^2+m+3n^2
order in hightest power first
-4m^2+3n^2+m
the answer is A
