Tuesday

January 27, 2015

January 27, 2015

Posted by **jae** on Saturday, May 26, 2012 at 5:48am.

- arithmetic -
**Reiny**, Saturday, May 26, 2012 at 9:03am7th term = -247 ---> a+6d = -247

18th term = -49 ---> a+17d =-49

subtract them:

11d = 198

d = 18

in a+6d = -247

a + 108 = -247

a = -355

sum(25) = (25/2)(-710 + 24(18)) = -3475

**Answer this Question**

**Related Questions**

math - Find the sum of the first 60 terms of the arithmetic sequence whose ...

algebra - can you check my answers please? What are the first three terms of the...

Algebra1 - Find the sum of the first 33 terms of the arithmetic sequence whose ...

math - Find the sum of the first 33 terms of the arithmetic sequence whose first...

Maths - 1..The first 2 terms of a geometric progression are the same as the ...

Algebra - True or False 1. – 5, – 5, – 5, – 5, – 5, … is an arithmetic sequence...

Math *URGENT - Please give the answers and solutions for each. 1.If the second ...

arithmetic - 1. The first and last term of an A.P are, a and l respectively, ...

arithmetic - 1. The first and last term of an A.P are, a and l respectively, ...

Precalculus - The 8th term in an arithmetic sequence is 5, and the sum of the ...