Question

The Sum of the rst n terms of an A.P. is given by:

Sn = n

2

[2a + (n − 1)d]. The following are the steps involved in making d as the

subject of the formula. Arrange them in sequential order.

(A) 2a + (n − 1)d = 2S

n

n

(B) d = 2

n 1

S

n

a n

− −









(C) Sn = n

2

[2a + (n − 1)d] ⇒ 2Sn = n[2a + (n − 1)d]

(D) (n − 1)d = 2S
Class 7 ​

Answer 1

Step-by-step explanation:

The formula says that the sum of the first n terms of our arithmetic sequence is equal to n divided by 2 times the sum of twice the beginning term, a, and the product of d, the common difference, and n minus 1. The n stands for the number of terms we are adding together.