Question

No idea at all!
Write the series in expanded form and find the sum:
(I will attach it in a bit!)
a. (-6 ∙ 1 + 14) + (-6 ∙ 2 + 14) + (6 ∙ 3 + 14) + (-6 ∙ 4 + 14) + (-6 ∙ 5 + 14) = -20

b. (-6 ∙ 1 + 14) + (-6 ∙ 5 + 14) = -8

c. (-6 ∙ 1 + 14) - (-6 ∙ 2 + 14) - (-6 ∙ 3 + 14) - (-6 ∙ 4 + 14) - (6 ∙ 5 + 14) = 36

d. (-6 ∙ 1 + 14) - (-6 ∙ 5 + 14) = 24

Answer 1

Please explain too! :)

Answer 2

I do not understand this one at all... super duper confused!

Answer 3

It says that it will iterate from 1 to 5.

Answer 4

I have no idea what that means haha... I also don't get how to read the pic... :(

Answer 5

[-6(1) + 14] + [-6(2) + 14] + [-6(3) + 14] ....... like this till 5.

Answer 6

so the answer is a then?

Answer 7

You simply take -6k+14 and you replace k with 1 to get -6(1) + 14

Then you reset and you replace k with 2 to get -6(2) + 14

Keep going and replace k with 3 to get -6(3) + 14

See the pattern?

Answer 8

and you got the 5 from the top of the symbol thingy right? what's the symbol thingy called? haha

Answer 9

10 + 2 - 4 - 10 - 16

Answer 10

and you substitute the 1 because k=1??

Answer 11

the symbol is sigma

Answer 12

and you keep going until the number above the symbol thingy? or the sigma? haha

Answer 13

yes

Answer 14

and then that would be your answer?

Answer 15

12 + 4 - 10 - 16
16 - 10 - 16
16 - 26
-20

Answer 16

I think you get the idea.

Answer 17

Sigma means summation.

Answer 18

@iheartfood

Answer 19

So the answer to this problem is a then? And you substitute numbers to the one on top of the sigma until you reach the number given??

Answer 20

*a is the answer then? haha phrased that really funny...

Answer 21

you got it iheartfood

Answer 22

Thanks you all! :) Really appreciate your help :D

Answer 23

And thanks to @jim_thompson5910 too! This thing only lets me give one medal/best answer... weird.. and thanks @ParthKohli sorry to bug you AGAIN! lol :O

Answer 24

dw let me give him

Answer 25

that's fine really, the medal system doesn't make much sense anyway...as long as you got help, that's what really matters