Answer
$ 2m^2+n^2 -8m$
Work Step by Step
Like terms must (1) be raised to the same power and (2) consist of the same variable (i.e. x and y are not like terms). It is also important to note that numbers are all like terms with each other when not multiplied by anything. Thus, combining like terms, we obtain:
$$ (6-5)n^2 + 2m^2 -8m \\ = 2m^2+n^2 -8m$$
