Question

Here are some numbers

Answer 1

Answer:

  15, 27, 39

  a[n] = a[n-1] +12; a[1] = 15

Step-by-step explanation:

The terms of an arithmetic progression have a common difference.

There are numbers in the given list that have differences of 5, 7, 12. The numbers with differences of 5 have already been listed. Other possible sequences are ...

  13, 20, 27 . . . . common difference of 7

  15, 27, 39 . . . . common difference of 12

The rule for the latter sequence is "each term is 12 more than the last" and the first term is 15.