5. Is the sequence arithmetic? If so, identify the common difference.

14, 21, 42, 77, ...

yes; 7

yes; - 7

yes; 14

no

6. What is the 12th term of the sequence 10, 6, 2, ...?

-16

-24

-34

-38

7. Find the missing term of the arithmetic sequence 22, ___, 34, ...

46

16

28

40

5.

aritmetic is same increase per term

14 to 21 is 7

21 to 42 is 21

7≠21

no

6.

decreases by 4 each time

an=a1+d (n-1)

an=10-4 (n-1)

n=12 for 12th term

a12=10-4 (12-1)

a12=10-4 (11)

a12=10-44

a12=-34

it is - 34

7.

missing term is y

22+n=y

y+n=34

22+n+n=34

22+2n=34

minus 22 from both sides

2n=12

divide both sides by 2

n=6

22+n=y

22+6=y

28=y

28 is answer

5. no

6. - 34

7. 28