Question

Someone help please . . . .
(Picture Below)

Answer 1

I'm sorry, I don't think I ever went over a question like that, and if I did it was 3 years ago and I don't remember.

Answer 2

I'm sure if you message stamp they can help you.

Answer 3

@PeterPan @phi @stamp Can anyone help ?

Answer 4

\[\huge \sum_{t = 1}^{18}(3t - 4)\]

Answer 5

@Kayy_Drizzyy which answer choice can you eliminate? Simply using reason.

Answer 6

Or we could pretend there aren't any choices...
Summation distributes
\[\huge \sum_{t=1}^{18}3t \ - \ \sum_{t=1}^{18}4\]

Answer 7

t = 18 ? right ?

Answer 8

more like t goes from 1 to 18

Answer 9

I did (3(18)-4 in my calc. but i got 50 instead of the answers in my answer choice. What am i doing wrong ?

Answer 10

Maybe you're just smarter than your calculator :D
\[\huge \sum_{t=1}^{18}3t \ = \ 3\sum_{t=1}^{18}t\]

Answer 11

Okay so whats next after that ?

Answer 12

@Kayy_Drizzyy You can eliminate the answer choice that has decimals, because we are dealing with whole numbers so our answer is going to be a whole number. Now we are narrowing down are choices.

Answer 13

sry, I wrote some wrong things there: you calculated a_18, but you were supposed to calcuate the sum of a_1 + a_2 + a_3 + .. + a_18

Answer 14

a_4 a_5 a_6 . . . . It keeps going until you get to 18. I understand that, but all do i have to do to get my correct answer ?

Answer 15

On second thought, we may as well just use the formula for the sum of a finite arithmetic series...
\[\huge \sum_{t=1}^{n}[a_1 + (t-1)(d)]=\frac{n(a_1 + a_n)}{2}\]

Answer 16

Just take n=18, and you're good to go :)

Answer 17

would it be like 3(18-4)/2 ?

Answer 18

n = 18 right?
a_1 is just the first term, which is just (3t - 4), evaluated at t =1
a_18 is just (3t - 4) evaluated at t = 18

Do the math :D

Answer 19

i got 25 as my answer i did 3(18)-4 and above you has it as divide it by 2 right ? So i did that and got 25 but on my answer choice one of them say 25.5 . would that be my answer ?

Answer 20

I read online it was just the average of the initial and terminal term, times the number of terms.\[t(1)=-1\]\[t(18)=50\]\[49*9\]

Answer 21

49*9 = 441

Answer 22

is that my answer ?

Answer 23

@Kayy_Drizzyy No I heard 49*9=24.. you may want to check your calculator.

Answer 24

Average of the initial and terminal term, times the number of terms...
Initial term : a_1
Terminal term : a_n
Number of terms : n

So yeah, @stamp

Answer 25

How is 49*9 24 really if you times 49 TIMES 9 you will get 441 ?

Answer 26

*chuckles*

Answer 27

@PeterPan :(

Answer 28

is 441 my answer guys ?

Answer 29

Silly @stamp
You're still stuck in the mysterious world of
\[\huge Z_{417}\]

Answer 30

:D

Answer 31

HELLO

Answer 32

OH, @Kayy_Drizzyy
Yeah, lol, it should be :)

Answer 33

Omg -_-

Answer 34

@Kayy_Drizzyy Confidence! C O N F I D E N C E

Answer 35

I just want to know if that's the correct answers . I dont want that to be wrong. then im going to be bad. You guys helped me thank you very much now i think my answer is 441 & i need to know if thats the 100% correct answer ?

Answer 36

@Kayy_Drizzyy Math, once you bother to understand it, is one of the few things in life in which you can be CONFIDENT. Yes, if the numbers say something, it is true. It does not matter if I say 9(49) is some bogus, you know math and you can be confident that 9(49)=441. No matter what I TELL YOU you can be confident of that.

Answer 37

Okay thank you @stamp lmao

Answer 38

@Kayy_Drizzyy I do not know 100% if it is the right answer, but @PeterPan seems like a pretty smart dude and together we both feel that it is a fair and educated response to the question.

Answer 39

Goodluck Kayy :)