Question

73. Find the common difference of an AP whose
first term is 5 and the sum of its first 4 terms
is half the sum of the next 4 terms.​

Answer 1

Answer:

Hence, the common difference of the given A.P. is 2.

Answer 2

Answer:

d =2

Step-by-step explanation:

let d is common difference of AP

now first 4 terms are 5, 5+d , 5+2d , 5+3d

and next 4 terms are 5+4d , 5+5f , 5+6d , 5+7d

given that, the sum of its first four terms is half of the sum of the next four terms. i.e.,

5 + 5 + d + 5 + 2d + 5 + 3d = 5 + 4d + 5 + 5d + 5 + 6d + 5 + 7d 2

20 + 6d = ( 20 + 22d )

2

20 + 6d = 10 + 11d

d = 2

hence, the common difference of the given A.P. is 2