Answer: [tex]\sum^{7}_{n=1} (-2+9n)[/tex]
Step-by-step explanation:
This is an arithmetic series with first term 7 and common difference 9, so the general formula for the nth term of the sequence is [tex]7+9(n-1)=7+9n-9=-2+9n[/tex].
The sequence has 7 terms, so the sigma notation is:
[tex]\sum^{7}_{n=1} (-2+9n)[/tex]
