Question

A store displays six computers on a shelf side–by–side. If the first computer is seven inches wide and each successive computer is two inches wider than the previous one, find the total width of the computers on the shelf.

Part 1: Describe the sigma notation used in answering the question above. (2 points)

Part 2: Show all your work and answer the question. (3 points)

Answer 1

Do you know how to start?

Answer 2

No

Answer 3

Well if I were to do this I would start out using the information given.. so we know that the first one is 7 inches, and after each one they get 2 inches wider. so it would be something like x+7 where x starts off at 0 and ends with 5.

Answer 4

this is a Arithmetic sequence.. each computer is a element and the distance is 2 and \[a_{1}\]equals 7

Answer 5

*sigh* I'll set it up for you:
\[\sum_{0}^{5}2x+7\]

Answer 6

to find the sum use this formula:

\[\sum_{n=1}^{k}a _{n} = \frac{ k }{2 }(a _{1}+a _{k})\] where K is the number of the last element u want to use and \[a _{1}\] is your first element

Answer 7

damn girl

Answer 8

to find \[a _{k}\] use :: \[a _{n}= a _{1} + (n-1)d\] \[a_{n} \] is the value of the element you want to use ... in this case would be \[a _{6}\]

Answer 9

after you find An then you use the formula to find the sum..

Answer 10

Yes okay thank you so much (:

Answer 11

damn girl

Answer 12

I got 72