Question

1. What are the first five terms of the sequence given by the formula a_n=6n+1

a. 7,13,19,25,31
b.1,7,13,19,25
c. 6,12,18,24,30
d.13,19,25,31,37
3. Write an explicit definition for the sequence -3, 1, 5, 9,...
a. a_n=-3+4(n-1)
b. a_n=-3+ 4n
c. a_n= -3+(n-1)
d. a_n= -3+4(n+1)

7. what is the 12th term of the sequence 20,16,12,...
a. -30
b. -20
c. -28
d. -24

8. Find the missing term of the arithmetic sequence 20, __, 32,...
a.42
b.18
c.34
d. 36
10. what is the 10th term of the sequences 625,125,25,...
a. 1/3,125
b. 1/

Answer 1

1) a. 7,13,19,25,31 ⇒ a(1) = 6(1) + 1 = 6 + 1 = 7.

3) a. a_n=-3+4(n-1)

7) a(n) = 20 - 4(n-1) ⇒ d. -24

8) 32 - 20 = 12 ; 12/2 = 6
20 + 6 = 26 This is the missing term.
26 + 6 = 32

10)
1 - 625 / 1 = 625
2 - 625 / 5 = 125
3 - 125 / 5 = 25
4 - 25 / 5 = 5
5 - 5 / 5 = 1
6 - 1 / 5 = 1/5
7 - 1/5 ÷ 5 = 1/25
8 - 1/25 ÷ 5 = 1/125
9 - 1/125 ÷ 5 = 1/625
10 - 1/625 ÷ 5 = 1/3125 Choice A.