Question

Write the sum using summation notation, assuming the suggested pattern continues.

-10 - 2 + 6 + 14 + ... + 110

Answer 1

First you can find the n value of the last term, 110, using the formula
\[n ^{th}\ term= a + (n-1)d\]
where the first term a = -10 and the common difference d = 8.
By substituting in the formula we get
\[110=-10+(n-1)8=-10+8n-8\ ............(1)\]
When the terms in equation (1) are rearranged the value of n can be found from
8n = 128 ...............(2)
Then the required summation can be found from:
\[\sum_{110}^{-10}=\frac{n}{2}(-10+110)\]

Answer 2

\[\sum_{n=0}^{15}(-10+8n)\]

Answer 3

\[\sum_{n=0}^{\infty}(-10+8n)\]

Answer 4

is the asnwer the firstone

Answer 5

Yes, it is the first summation that you posted.