Question

the sum of 4th term and 16th term is 8 find the sum of 19th term​

Answer 1

Answer:

T

4

+T

8

=24

T

6

+T

10

=34

⇒a+3d+a+7d=24

⇒2a+10d=24

⇒a+5d=12 …………(1)

⇒a+5d+a+9d=34

⇒2a+14d=34

⇒a+7d=17 …………(2)

Equation (2) - Equation (1)

⇒2d=5

⇒d=

2

5

a=12−5d=12−

2

25

=

2

−1

AP=

2

−1

,2,

2

9

,….

solution