Question

9. The sum of the first n terms can be solved using the formula a. Sn = (a + an) b. Sn = (an-an) c. Sn = n(at an) d. Sn = n(a1 - an) b​

Answer 1

Answer:

it is

N

Sn= ------ ( a1+an)

2

Answer 2

Answer:

Step-by-step explanation:

the sum of the first n terms=n/2(a+a+(n-1)d)