Saturday

January 31, 2015

January 31, 2015

Posted by **Anonymous** on Sunday, November 1, 2009 at 10:26am.

Find the sum:

it has the sigma sign with 12 at the top, (10k-8)(6k+7) in the middle and k=1 at the bottom

- math- Algebra 2 -
**jim**, Sunday, November 1, 2009 at 10:51amIt just means, add:

the value of (10k-8)(6k+7) when k=1

plus

the value of (10k-8)(6k+7) when k=2

plus

the value of (10k-8)(6k+7) when k=3

plus

... (and so on, 4, 5, to 9, 10)...

the value of (10k-8)(6k+7) when k=11

plus

the value of (10k-8)(6k+7) when k=12

So you could just do it by calcuating out:

the value of (10k-8)(6k+7) when k=1 is 26

plus

the value of (10k-8)(6k+7) when k=2 is 228

and so on.

It mightn't be a bad idea to do that anyway, since you will understand it thoroughly and be sure of your answer.

However, there are short-cuts.

It may be that you've already covered these in your class, or it may be that you were given this exercise so that you'll appreciate them when you do cover them! :-)

There is a formula for the sum of x from 0 to n and a formula for the sum of x^2 from 0 to n. You can probably find them in your text.

By multiplying out the expression, we can then use those formulas.

- math- Algebra 2 -
**Anonymous**, Sunday, November 1, 2009 at 11:23amall right great thank you so much!

- math- Algebra 2 -
**jim**, Sunday, November 1, 2009 at 11:39amYou're welcome!

**Answer this Question**

**Related Questions**

Algebra - find the indicated sum not sure how to type the sigma sign, but here ...

Algebra II - Please help-I need to write 4+6+8+10 in sigma notation would it be ...

algebra - find the indicated sum 4 on top of sigma symbol i=1 on the bottom of ...

algebra - Suppose that these 15 measurements are respectively labeled x1,x2,..,...

Algebra 2 - I can't figure out how to find the n on top of the sigma. I have ...

Algebra 2 - I can't figure out how to find the n on top of the sigma. I have the...

Pre-Calc-Please check answer - 1.Write 4+6+8+10 in sigma notation: I came up ...

Pre-Calc-Please check answer - 1.Write 4+6+8+10 in sigma notation: I came up ...

Algebra 2 / Trig - Here is the problem that I'm having trouble with: Rewrite ...

Math (sigma stuff!) - Hi! Looking to find n∑k=1 8(k/n) (n is supposed to ...