Question

Fill in the blank in the following table, given that a is the first term, d the common difference, and a_n nth term of the AP:

a	d	n	an
-18	______	10	0

Answer 1

a	d	n	an
-18	2	10	0

Explanation:

Given that

a = -18, n = 10, a_n = 0, d = ?

We know that,

a_n = a + (n - 1) d

0 = -18 + (10 - 1) d

18 = 9d

d = `18/9`

d = 2

Hence, common difference, d = 2