# Algebra

posted by .

I am so lost on these problems.

Write a geometric sequence that starts with 3 and has a common ratio of 5. What is the 23rd term in the sequence.

Write an arithmetic sequence that has a common difference of 4 and the eighth term is 13. What is the first term? What is the 23rd term in the sequence.

Write an arithmetic sequence where 12 is the first term of 12, and the tenth term is 39. What is the first term? What is the 23rd term in the sequence.

Two consecutive terms of a geometric sequence, in order are 10 and 12. What is the ratio. What is the term before 10? What is the term after 12?

• Algebra -

well, they have said that
a=3
r=5
The 23rd term is thus 3*5^22
That is, you start with 3 and multiply by 5 22 more times to get to the 23rd term.

Next, we have
a + 7*4 = 13
so, a = -15
T23 = -15 + 22*4

Any two consecutive terms of a geometric sequence have a common ratio. In this case, we have

r = 12/10 = 6/5
So, to get the term before 10, divide by 6/5
To get the term after 12, multiply by 6/5

## Similar Questions

1. ### Math

A sequence is formed by adding together the corresponding terms of a geometric sequence and and an arithmetic sequence.The common ratio of the geometric sequence is 2 and the common difference of the arithmetic sequence is 2.The first …
2. ### pre algebra

solve whether the sequence is arithmetic or geometric if it is arithmetic or geometric,state the common difference or common ratio and write the next three terms of the sequence 10,18,26,34
3. ### Maths

Eric thinks of 2 sequences.One is geometric and the other arithmetic.Both sequences start with the number 3.The common ratio of the geometric sequence is the same as the common difference of the arithmetic sequence.If the 6-th term …
4. ### Maths

1..The first 2 terms of a geometric progression are the same as the first two terms of an arithmetic progression.The first term is 12 and is greater than the second term.The sum of the first 3 terms od the arithmetic progression is …
5. ### Algebra ll

Help please, I don't understand how to do this... Give an example of an arithmetic sequence that is found in the real world. Find the common difference and write a recursive and iterative rule for the sequence. Use one of the rules …
6. ### math

Determine whether each sequence is arithmetic or geometric. Find the next three terms. 1. 14, 19, 24, 29, . . . (1 point) geometric, 34, 39, 44 arithmetic, 32, 36, 41 arithmetic, 34, 39, 44 *** The sequence is neither geometric nor …
7. ### Algebra

True or False 1. – 5, – 5, – 5, – 5, – 5, … is an arithmetic sequence. 2. In an arithmetic sequence, it is possible that the 13th term is equal to its 53rd term. 3. In an arithmetic sequence, the common difference is computed …
8. ### Math Help!!!

determine whether each sequence is arithmetic or geometric. find the next three terms. 1. 14,19,24,29.... geometric, 34,39,44 arithmetic,32,36,41 arithmetic 34,39,44**** the sequence is nether geometric nor arithmetic 2. -4,8,-16,32.... …
9. ### math

The 1st,5th,13th term of an arithmetic sequence are the first 3 terms of geometric sequence with a common ratio of 2. If the 21st term of the arithmetic sequence is 72, calculate the sum of the first 10 terms of the geometric sequence.
10. ### math

still need help: Write an arithmetic sequence that has a common difference of 4 and the eighth term is 13. What is the first term?

More Similar Questions