Given the sequence: 1,-1/3,1/9,-1/ find
a) the fifteenth term.
b) the sum of the 5th term to be 10th term

We can find the following pattern:

We can deduce the generic rule

And thus

With this rule, you can compute the 5th, 6th, 7th, 8th, 9th and 10th element and sum them.

part 1 answer = 8

part 2 answer = 72

step-by-step explanation:

part 1 explanation = add all of the numbers, then divide by how many numbers you have. so, 200/25 = 8.

part 2 explanation = not gonna lie, this is hard to explain, so just google how to do it.

from the figure we get,

the x axis shows   the months and,

the y-axis shows the number of satisfied customer.

each line or each cell in upward direction (y-axis) shows 500.

the appropriate scale for the y - axis is: -

a = 2000 customers

b = 4000 customers

c = 6000 customers

d = 8000 customers

e = 10000 customers

f = 12000 customers

g = 14000 customers