Answer:
Only the third sequence is arithmetic
Step-by-step explanation:
If the sequence has a common difference, then it is arithmetic. To find the common difference, substract a term from the next term.
First sequence:
10 - 20 = -10 5 - 10 = -5 The differences are not the same, so the sequence is NOT arithmetic
Second sequence:
-6 - (-3) = -3 -18 - (-6) = -12 The differences are not the same, so the sequence is NOT arithmetic
Third sequence:
10 - 5 = 5 15 - 10 = 5 20 - 15 = 5 The differences are the same, so the sequence is arithmetic
Fourth sequence:
10 - 5 = 5 20 - 10 = 10 The differences are not the same, so the sequence is NOT arithmetic
