Question

Based on the pattern, what are the next two terms of the sequence?

Answer 1

Did you notice that we keep doing the same steps, exactly 6?
15-9=6
21-15=6
27-21=6

That means we are adding 6 at every step. Therefore the next two elements must be
27+6=33 and 33+6=39

Answer 2

33 , 39

Explanation:

given

9 , 15 , 21 , 27

there is a common difference between consecutive terms, that is

15 - 9 = 21 - 15 = 27 - 21 = 6

to obtain terms in the sequence add 6 to the preceding term

27 + 6 = 33

33 + 6 = 39

the next two terms are 33 and 39