Answer:
-20 + 7(n-1)
Explanation:
It's already given that d, or the common difference, is 7. The only thing left to do is to find the first term of this sequence.
We are given that
= 50.
If we subtract the common difference 10 times we can find the first term.
- 7 x 10 = -70
50 - 70 = -20
The first term is -20. The only choice that shows this is the first one.