Question

6) Find the common difference of an AP whose 1 st term is 5. the sum of its first 4 terms is half
the sum of the next 4 terms.​

Answer 1

Answer:

differ =2

Step-by-step explanation:

First term = a = 5

Sum of 1st 4 terms = 1/2 sum of next 4 terms

a+(a+d)+(a+2d)+(a+3d) = 1/2[(a+4d)+(a+5d)+(a+6d)+(a+7d)]

4a+6d = 1/2[4a+22d]

2

2[4a+6d] = 4a+22d

8a+12d = 4a + 22d

8a - 4a = 22d - 12d

4a = 10d

2a = 5d

2(5) = 5d

d = 2