Which expression is equivalent to?

Answer:
[tex]m^3+m^2[/tex]
Step-by-step explanation:
First, distribute [tex]-m^2[/tex] to the terms inside the parentheses and then, combine like terms. We get:
[tex]2m^2-m^2(7-m)+6m^2\\=2m^2-7m^2+m^3+6m^2\\=m^3+m^2[/tex]
Thus, fourth answer choice is right.