Respuesta :

reistheebeast

Answer:

3

Step-by-step explanation:

It is 3 because fi you multiply 5 by 3 you get 15, and if you multiply 10 by 3 you get 30. Subtract 30 by 6 and get 24. And finally, if you multiply 2 by 3 it gives you 9. 9+12= 21.