Question

If the sum of first four terms of an AP is 8, then find its first term?

Answer 1

I think it's enough.

I hope it will help you.

Answer 2

ANSWER :

Let the terms be (a - 3d), (a - d), (a + d), (a - 3d)

Sum = 8

a - 3d + a - d + a + d + a + 3d = 8

4a = 8

a = 8/4

a = 2

The first term is 2

Whenever such questions come always take the AP like this.

When there are 3 terms, take the AP as (a-d), a, (a+d) so when the sum is added the d is cancelled

When there are 2 terms, take the AP as (a-d) and (a+d)

When there are 5 terms, take the AP as (a-2d), (a-d), a, (a+d), (a+2d)

In all these, when we do the addition, the d is cancelled and we get only a

Pls follow......