Question

The algebraic form of an AP is 8n-4 prove that the sum of n terms of this sequence is a perfect square​

Answer 1

ANSWER

Given, arithmetic sequence X

n

=5n+3

a. The first term of the sequence, put n=1

X

1

=5×1+3=8

b. d=5 (coefficient of n be the common difference)

The remainder divide by 5=3.

(

5

8

=3,

5

13

=3,

5

18

=3,etc)

Answer 2

Answer:

50

Step-by-step explanation:

The given AP is 3, 8,13,18....

Here, a = 3 and d = 8 – 3 = 5

∴ a30 – a20

=[3 + (30 – 1)5]- [3 + (20 – 1)5]  

= 148 – 98 = 50

Thus, the required value is 50