Question

What is the rule in this sequence (0,21) (1,18) (2,15) (3,12) (4,9) (5,6) (6,3) (7,0) (8,-3) (9,-6) (10,-9)

Answer 1

x + 1 & y - 3

Explanation:

Because... the x-values are going up by 1 digit each and the y-values are going down by 3 digits each.