Question

Which sequences are arithmetic? Check all that apply.

Answer 1

ANSWER

3. 18, 5.5, –7, –19.5, –32, …

and

5. 16, 32, 48, 64, 80

EXPLANATION

An arithmetic sequence has a constant difference.

1. –5, 5, –5, 5, –5, … is not an arithmetic sequence because 5--5≠ -5-5

2. 96, 48, 24, 12, 6 is not an arithmetic sequence because 48-96≠ 24-48

3. 18, 5.5, –7, –19.5, –32, … is an arithmetic sequence because there is a constant difference of

$5.5 - 18 = - 12.5$

4. –1, –3, –9, –27, –81, … is not an arithmetic sequence because

$- 3 - - 1 = - 9 - - 3$

5. 16, 32, 48, 64, 80 is also an arithmetic sequence because

$32 - 16 = 48 - 32$

Answer 2

-5,5,-5,5,-5,5,-5,5,-5