Which sequences are arithmetic? Select three options. –8.6, –5.0, –1.4, 2.2, 5.8, …
2, –2.2, 2.42, –2.662, 2.9282, …
5, 1, –3, –7, –11, …
–3, 3, 9, 15, 21, …
–6.2, –3.1, –1.55, –0.775, –0.3875, …

The sequences are arithmetic

1).-8.6, -5.0, -1.4, 2.2, 5.8

2).  5, 1, -3, -7, -11

3). -3, 3, 9, 15, 21

Step-by-step explanation:

If a sequence is a an AP then there is a common difference d.

1) Check sequence 1

-8.6, -5.0, -1.4, 2.2, 5.8

-5.0 - - 8.6 = 3.6

-1.4 - -5.4 = 3.6  It is an AP

2) Check sequence 2

2, -2.2,2.42, -2.662, 2.9282

-2.2 - 2 = -4.2

-2.662 - 2.42 = -5.082 Not AP

Similarly AP sequences are

5, 1, -3, -7, -11

-3, 3, 9, 15, 21