Question

U we given APIs +/.
Example 4 : Which term of the AP:21, 18, 15...is - 81 Also, is any term 0? Give
reason for your answer.​

Answer 1

Answer:

8th term

Step-by-step explanation:

In APs, nth term is given by a + (n - 1)d , a is first term and d is common difference.

Here,

a = first term = 21

d = 18 - 21 = - 3

Let nth term be 0.

= > 0 = 21 + (n - 1)(-3)

= > - 21 = (n - 1)(-3)

= > (-21)/(-3) = n - 1

= > 7 = n - 1

= > 8 = n

8th term is 0