Answer: 1,-1
Step-by-step explanation: 2,1,0,-1,-2. the common difference is 1
2, 1, 0, -1, -2
u just minus/subtract -1... for example the first one, 2-1 = 1 so the next one will be 1. 1-1 = 0. 0-1 = -1. and so on...
