Friday

April 25, 2014

April 25, 2014

Posted by **Trudy** on Saturday, January 20, 2007 at 11:14pm.

Alright so in an arithmetic squence the difference d between any two successive numbers is constant. So if the first term is x, then the second term is (x+d), and the third term is (x+2d), etc. up to the tenth term in this case which is (x+9d). We know that the eighth term is 5 so this gives...

x+7d=5

and we know that the sum of the first ten terms is 20 which gives...

x+(x+d)+(x+2d)+(x+3d)+...+(x+9d)=20

or..

10x+45d=20

Solve these two equations for x and d..

x+7d=5

10x+45d=20

I get... d=1.2 and x=-3.4

Hope that helps

**Related Questions**

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

maths - 1) The first term of arithmetic progression is -20 and the sum of it's ...

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

Math - A sequence is formed by adding together the corresponding terms of a ...

Math for Educators - The first difference of a sequence is 8, 12, 16, 20,... The...

Mathematics : Arithmetic Sequence - The 5th term and the 8th term of an ...

Arithmetic Sequence - Given the third term of an arithmetic sequence less than ...

arithmetic - Given that an arithmetic sequence has a common difference of 5 and ...

arithmetic - an arithmetic progression has 20 terms. the sum of all the even ...

Maths - 1) In the arithmetic progression, the 8th term is twice the 4th term and...