Question

Chose the correct answer

If an=3n-1 then the value of S2
is_______?
A)5
B)7
C)2
D)0​

Answer 1

Step-by-step explanation:

If n = 1

a1 = 3(1) - 1 = 3 - 1 = 2

If n = 2

a2 = 3(2) - 1 = 6 - 1 = 5

d = a2 - a1 = 5 - 2 = 3

Sn = n/2 + (2a + (n - 1)d)

S2 = 2/2 + (2(2) + (2 - 1)(3))

S2 = 1 + (4 + (1)(3))

S2 = 1 + (4 + 3)

S2 = 1 + 7

S2 = 8

Answer 2

Answer:

option B is the correct answer..

Step-by-step explanation:

hope it's helpful