In the arithmetic sequence with 2n + 1 terms, if the sum of all odd terms is 165 and the sum of all even terms is 150, then n is equal to () A. 9B. 10C. 11D. 12

In the arithmetic sequence with 2n + 1 terms, if the sum of all odd terms is 165 and the sum of all even terms is 150, then n is equal to () A. 9B. 10C. 11D. 12

From the odd number term and S1 = (n + 1) (a1 + A2N + 1) 2 = (n + 1) × 2An + 12 = (n + 1) an + 1 = 165, ① even number term and S2 = n (A2 + A2N) 2 = n × 2An + 12 = Nan + 1 = 150, ② n + 1n = 165150, the solution is n = 10

In the arithmetic sequence with 2n + 1 terms, if the sum of all odd terms is 165 and the sum of all even terms is 150, then n is equal to ()
A. 9B. 10C. 11D. 12

From the odd number term and S1 = (n + 1) (a1 + A2N + 1) 2 = (n + 1) × 2An + 12 = (n + 1) an + 1 = 165, ① even number term and S2 = n (A2 + A2N) 2 = n × 2An + 12 = Nan + 1 = 150, ② n + 1n = 165150, the solution is n = 10

In the arithmetic sequence with 2n + 1 terms, if the sum of all odd terms is 165 and the sum of even terms is 150, what is n equal to?

Let a (n + 1) 165 = (n + 1) * a (n + 1) 150 = n * a (n + 1), then a (n + 1) = 165-150 = 15, n = 10