Question

The sum of 5th and 10th terms of an A.P. is 75 and 8th and 10th terms is 135. Find the first four terms of the A.P.​

Answer 1

Answer:

here is the answer

Step-by-step explanation:

Here,

a

4

=a+3d

a

8

=a+7d

Therefore,

a+3d+a+7d=24

2a+10d=24

a+5d=12 …… (1)

Again,

a

6

=a+5d

a

10

=a+9d

Therefore,

a+5d+a+9d=44

2a+14d=44

a+7d=22 ……. (2)

Solving equations (1) and (2), we get

d=5 and a=−13

Therefore,

a

1

=a=−13

a

2

=a+d=−13+5=−8

a

3

=a+2d=−13+10=−3

Hence, this is the required result.