1. ## Algebra Summation

hey guys, im having a bit of trouble with some questions.
Hopefully someone can help me out.

1. ∑[i=1 to n]Xi

where X = {8,10,9}

2. ∑[i=1 to 3] (Xi + a)Yi

Where X = {8,10,9}
Y = { 108, 101, 103, 94}
and a is a constant... a = 11

Hopefully the format of the question makes to everyone, it wouldnt let me copy and paste the proper format.

Thanks to anyone who helps!

2. ## Re: Algebra Summation

Originally Posted by kay1740
hey guys, im having a bit of trouble with some questions.
Hopefully someone can help me out.

1. ∑[i=1 to n]Xi

where X = {8,10,9}

2. ∑[i=1 to 3] (Xi + a)Yi

Where X = {8,10,9}
Y = { 108, 101, 103, 94}
and a is a constant... a = 11

Hopefully the format of the question makes to everyone, it wouldnt let me copy and paste the proper format.

Thanks to anyone who helps!
Hi kay1740,

$\sum_{i=1}^{n}X_{i}\mbox{ where }X=\{8,10,9\}$

The set $X$ contains three elements, so you can take, $X_{1}=8,~X_{2}=10\mbox{ and }X_{3}=9$

$\sum_{i=1}^{3}X_{i}=X_{1}+X_{2}+X_{3}$

Hope you can continue.

4. ## Re: Algebra Summation

Hi Sudharaka,

Is it possible that you could help me with the 2nd problem as well?

5. ## Re: Algebra Summation

Originally Posted by kay1740
Hi Sudharaka,

Is it possible that you could help me with the 2nd problem as well?
No, the X and Y data would have to be of the same length for us to help you with that

CB

6. ## Re: Algebra Summation

No, they don't have to be of the same length - because the question puts a restriction using numbers from 1 -3. Therefore, the only #'s in the Y data that would be used are 108, 101, and 103. I'm just not sure what summation rules to apply to the question in order to get the answer.

7. ## Re: Algebra Summation

Originally Posted by kay1740
No, they don't have to be of the same length - because the question puts a restriction using numbers from 1 -3. Therefore, the only #'s in the Y data that would be used are 108, 101, and 103. I'm just not sure what summation rules to apply to the question in order to get the answer.
Ok. Then the $X$ values would be the same as we have taken previously and the corresponding $Y$ values would be,

$Y_{1}=108,~Y_{2}=101\mbox{ and }Y_{3}=103$

Hope you can continue.

8. ## Re: Algebra Summation

heh alright, doesnt help too much.

But thanks guys