Answer:
Step-by-step explanation:
AS the top line progresses by 1, the bottom line progresses by 2.
So I'm going to fill in the top line from 3 to 8
1 2 3 4 5 6 7 8
3 5 7 9 11 13 15 17
The number that goes underneath the 8 is 17
Now we wonder how you get 21 in the second line
9 10
19 21
So the two answers you want are 17 on the bottom line and 10 on the top line.
