Question

i have to draw it...
Which of the following is equivalent to ...

Answer 1

\[\sum_{n=4}^{8}-3n-4\]

choices:

110
–110
–88
88

Answer 2

the answer is -110. Do you need an explanation?

Answer 3

yes

Answer 4

OK...\[S_{n}=(n(a_{1}+a_{n}))/2\]
You need to do this twice: once for 1-8, then once for 1-3. Because to find 4-8, you subtract sum of 1-3 from 1-8.