- #1
TheRedDevil18
- 408
- 1
Homework Statement
The sum of the first 9 terms of an arithmetic series is 216. The first, third and seventh terms of the series form the first three terms of a Geometric pattern. Find the first term and the common difference of the arithmetic pattern.
Homework Equations
The Attempt at a Solution
S9 = 9/2(2a+8d) = 216
S3 = T1+T3+T7
Completely stuck and need help
Last edited by a moderator: