Answer:
the answer is 12m + 4
Explanation:
you do the distributive property which is 3*2m and then 3*4 and you get 6m+12 and then you do it again which you do 2*3m and then 2*-4 and you get 6m-8 and then you get 6m+12+6m-8 and you just add your like terms to get 12+4
hope this helped