Question

how many terms of the AP 22,20,18,_____ should be taken so that their sum is zero?​

Answer 1

Answer:

$n = 12.$

Step-by-step explanation:

$ap \: \: \: \: \: \: 22 \: \: \: \: \: 20 \: \: \: \: \: 18 \: \: \: \: \: \: ... \\ \\ a = 22 \: \: \: \: \: \: \: \: \: \: \: d = 20 - 22 = - 2 \\ \\ s(n) = \frac{n}{2} (a + (n - 1)( - 2)) = 0 \\ \\ \\ a + (n - 1)( - 2) = 0 \\ \\ 22 = 2(n - 1) \\ \\ n - 1 = 11 \\ \\ n = 12.$