Question

Find the sum of the first ten terms of the sequence -4, 1, 6, ........41 in the tenth term. The answer is 185. I need help finding the rate, and the set up of the equation, I can't seem to figure it out.

Answer 1

This is an Arithmatic progression where each term is 5 more than the previous term

Answer 2

In such a case, the value of the nth terms is given by the formula
\[s _{n} = n/2 (a + l)\]
where sn stands for sum

a = first term which is -4 in this case
l = last term which is 41 in this case
n = no of term u want to find which is 10 in yr case

Answer 3

so putting in the values u get
\[s _{10} = 10/2 (-4 + 41) = 5 x 37 = 185\]

Answer 4

Does this work for you????

Answer 5

OMG!!!! YEEEEESSSSS!!! That is the most elaborate answer I have ever gotten EVER!!! Thank you sooooo much!!!!!!!!!

Answer 6

I'm a teacher by profession, so I try to giv ans which r crystal clear..........
Medal for me !!! :)

Answer 7

Well I wish you were my teacher!! I have been having such a hard time understanding math this semester.... Thank you so much, all I needed was for the break down!! Thank you thank you thank you!!!

Answer 8

Good Job Harkirat...that's the way I would have explained it

Answer 9

Exactly edbraunh!!

Answer 10

thanks edbraunch u r kind

Answer 11

I am frm India and I am already helping a kid in US thru e-tuition so I know how to giv solution so tht the other party understands

Answer 12

You are a great teacher I thank you again to very much!!! Your one of a kind =)))

Answer 13

U r most welcome !!
I suggest you collect all the formulas related to Arithmetic progression, understand the use of each one and memorize them. Then u will b on top of yr sums (and hopefully yr class too!!)

Answer 14

Thank you!! And I will