Question

Find the 21st term (from the last term)
of the A.P. 10, 7, 4,-62.​

Answer 1

Step-by-step explanation:

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Answer 2

Given :

A.P. 10, 7, 4, -62.

To find :

21st term ( from the last term) of the given A.P.

Solution :

The formula for finding any term in the given Arithmetic Projession is

Tn = a + (n - 1) d

where a is the first term of the A.P.

d is the difference between the two terms of the A.P.

As we have to find out 21 St term ( from the last term ) of the A.P.

Hence here a = - 62.

So our A. P. will be

-62, -59, -56, -53, -50. . .

Now we have to find ' d'

- 59 - (-62) = -59 + 62

= 3

Hence d = 3

T₂₁ = - 62 + ( 21 - 1) 3

= - 62 + (20 ) 3

= - 62 + 60

= - 2

Hence 21st term ( from the last term ) of the A.P. is - 2.