The 7th term of an AP is −4 and its 13th term is −6. Find the AP.
Question:

The 7th term of an AP is −4 and its 13th term is −6. Find the AP.

Solution:

We have:
T7 = a + (n – 1)d
⇒ a + 6d = -4           …(1)

​T13 = a + (n – 1)d
⇒ a + 12d = -16          …(2)
On solving (1) and (2), we get:
a = 8 and d = -2

Thus, first term = 8 and common difference = -2

∴ The terms of the AP are 8, 6, 4, 2,…