Question

Check my answers please?

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. Correct answer is a (since when you are not given the n values, it is implied that the first value is 1).
3. Correct answer is a (a(n)=-3+4(1-1)=-3).
7. The pattern is to reduce the previous value by 4, thus the 12th term of the sequence is -24 (a(n)=20 - 4(n-1)=20 - 4(12-1)=-24).
8. Missing term is 26 (32+20=52; 52/2=26).
10. Pattern is 625/1=625; 625/5=125; 125/5=25; 25/5=5, thus. the 10th term is 1/3125 (answer a).