Respuesta :

Answer:

m + 8

Step-by-step explanation:

you start with the original number of marbles, m, and you ADD 8 more to the group.

Original number (m) + 8 more

M = 8

Answer:

It would be the third one! :)

Step-by-step explanation: Because it says the number of marbles is represented by M then it says he ADDS 8 more to the bag meaning it's addition! :)