Question

I have to send you the question

Answer 1

The given expression fro the sum of n terms:

`\begin{gathered} S_n=(n)/(2)(a_1+a_n) \\ \text{ Where: }a_1\text{ is the firm term \& }a_n\text{ is the last term} \end{gathered}`

From the given question we have:

`a_1=8,a_n=79,\text{ n =6}`

Substitute these value in the expression of sum of n terms

`\begin{gathered} S_n=(n)/(2)(a_1+a_n) \\ S_6=(6)/(2)(8+79) \\ S_6=3(87) \\ S_6=3*87 \\ S_6=261 \end{gathered}`

So, sum of 6 terms is 261