Posted by **Aliza** on Monday, January 21, 2013 at 5:16am.

Find the no. of terms

1. 3,5,7...33

2.-5,-1,3,...75

Solve each problem.

1. In the Arithmetic sequence 5,8,11,14.... what is n if a sub n is 32?

2.Find the sum of the first 20 terms of the arithmetic sequence -15,-7,31,43...

- Math -
**Reiny**, Monday, January 21, 2013 at 10:34am
1. term(n) = a+(n-1)d

you have a = 3, d = 2 , n = ??

33 = 3 + (n-1)(2)

30 = 2n - 2

28 = 2n

n = 14 ------ there are 14 terms

do the 2nd one the same way

for the other two, I don't know how you defined a sub n

for the last:

first find the number of terms in the same way I showed you

you have a = -15 , d = 12 , n = ?

once you find a and d

use

Sum(n) = (n/2)(2a + (n-1)(d) )

- Math -
**Anonymous**, Tuesday, January 22, 2013 at 6:52am
Thank you so much . 1. In the Arithmetic sequence 5,8,11,14.... what is n if an is 32?

1. In the Arithmetic sequence 5,8,11,14.... what is n if n is 32?

## Answer This Question

## Related Questions

- Math *URGENT - Please give the answers and solutions for each. 1.If the second ...
- math - in an arithmetic sequence whose first term is 4, the 1st, 3rd and 7th ...
- math - in an arithmetic sequence the common difference is equal to 2.the first ...
- math! - george entered a function into his calculator andfound the following ...
- Arithmetic Sequence Help! - The sum of 3 consecutive terms of an arithmetic ...
- maths - the sum of the first nine terms of an arithmetic sequence 216. The 1st, ...
- Math - an = 3n - 1 Answer 2, 3, 4, 5 2, 5, 8, 11 -2, -5, -8, -11 4, 7, 10, 13 3...
- Math - Question 1 Write the first four terms of the sequence whose general term...
- Math PLEASE HELP PLEASE PLEASE PLEASE - Question 1 Write the first four terms ...
- Further mathematics - An exponential sequence (GP)of positive terms and a linear...

More Related Questions