Tuesday

March 31, 2015

March 31, 2015

Posted by **PJ** on Sunday, January 6, 2013 at 9:28pm.

- Geometric series -
**Reiny**, Sunday, January 6, 2013 at 11:03pmif sum(6) = 378 and sum(5) = 186

then term(6) = 378-186 = 192

so

ar^5 = 192

ar^3 = 48

divide them

r^2 = 4

r = ±2

if r=2, then a(8) = 48 --->a = 6

if r = -2, then a(-8) = 48 --- a = -6

if a= 6, r=2, t(10) = 6(2^9) = 3072

if a= -6, r=-2 , t(10) = -6(-2)^9 = 3072

if a=6, r=2, sum(10) = 6(2^10 - 1)/1 = 6138

if a=-6,r=-2, sum(1) = -6((-2)^10 - 1)/-2-1) = 2046

**Answer this Question**

**Related Questions**

FUNCTION 11..HELP! - The sun of the first five terms of a geometric series is ...

Math(arithmetic & Geometric Series) - 1)The sum of 6 terms of an arithmetic ...

math studies - An arithmetic series has a first term of -4 and a common ...

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, ...

Geometric Series (Algebra 2) - I need some assistance or a formula when trying ...

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

Geometric - 1) The sum of last three terms of GP having n terms is 1024 time the...

Math - Q: Determine the sum of the first seven terms of a geometric series in ...

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