Answer:

30 is the answer

9 + 3 = 12

9 + 12 = 21

9 + 21 = 30

HOPE IT HELPS

Answer:

30,39,48

Step-by-step explanation:

3+9=12

12+9=21

21+9=30

30+9=39

39+9=48

add the number of the last term to 9

Pa brainliest thank