- #1
- 1
- 0
Homework Statement
The sum of the first 4 terms in an arithmetic series is -8 and the sum of the first 5 terms is 85. Determine the first term and the common difference.
Homework Equations
tn = a + (n-1)d
Sn = n/2 (2a + (n-1)d)
I think you forgot to type in this section.The Attempt at a Solution