Answer :

The rule of arithmetic progression is -15, -9, - 3, 3, 9, 15.

What do w mean by Arithmetic progression?

  • An arithmetic progression is a sequence of numbers that has a fixed common difference between any two consecutive numbers (A.P.).
  • A.P.'s example is 3,6,9,12,15,18,21,...

So, to find the rule:

  • Given:  _____, -9, ______, 3, 9
  • Then, 9 - 3 = 6
  • So, the difference is 6.

Therefore, the rule is -15, -9, - 3, 3, 9, 15.

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