- Questions

1.an = 3n - 1

2. an = 2(2n - 3)

3.an = 4^n

4.an = (2/3)^n

5. an = (-1)^n(n + 5)

6. an = (-1)^n + 1(n + 6)

7. an= n+3/2n-1

8. a1 = -5 and an = an-1 - 3 for n ≥ 2

9. a1 = -6 and an = -2an-1 for n ≥ 2

10.a1 = 4 and an = 3an-1 + 2 for n ≥ 2

11. Find a8 when a1 = -10, d = -3.

3 points

Question 16

Use the formula for the general term (the nth term) of an arithmetic sequence to find the indicated term of the sequence with the given first term, a1, and common difference, d.

Find a21 when a1 = 28, d = -5.

Answer

-77

128

-100

-72

3 points

Question 17

Write a formula for the general term (the nth term) of the arithmetic sequence. Then use the formula for an to find a20, the 20th term of the sequence.

1, 4, 7, 10, 13, . . .

Answer

an = 3n + 2; a20 = 62

an = n + 3; a20 = 23

an = 3n - 2; a20 = 58

an = 2n - 3; a20 = 37

3 points

Question 18

Write a formula for the general term (the nth term) of the arithmetic sequence. Then use the formula for an to find a20, the 20th term of the sequence.

25, 16 , 7, -2, . . .

Answer

an = -9n + 25; a20 = -155

an = -9n + 34; a20 = -146

an = 9n - 25; a20 = 155

an = 9n - 34; a20 = 146

3 points

Question 19

Solve the problem.

The population of a town is increasing by 200 inhabitants each year. If its population at the beginning of 1990 was 27,842, what was its population at the beginning of 1998?

Answer

222,680 inhabitants

29,442 inhabitants

29,242 inhabitants

445,360 inhabitants

3 points

Question 20

Find the indicated sum.

Find the sum of the first 50 terms of the arithmetic sequence: 3, -4, -11, -18, . . .

Answer

-8600

-8425

-347

-8420

3 points

Question 21

Find the indicated sum.

Find the sum of the first 48 terms of the arithmetic sequence: 2, 4, 6, 8, . . .

Answer

98

2359

2400

2352

Just reply if you can check my work and i will post my answers again