Question

find sum of first 12 term of AP 2,7,12,...............​

Answer 1

Answer:

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

S12 = 12/2 ( 4 + 11(5))

S12 = 6(4+55)

S12 = 6(59)

S12 = 354

Answer 2

Answer:

1. sn=n/2 (2(2) + n-1 d
2. sn 6 ( 4+ 55)
3. sn 6 ( 59)
4. sn=356