Question

find the sum of first 24 terms of the list oif number whose n th term is give by an =3+2n

Answer 1

an = 3+2n

So, a1 = 3 + 2*1 = 5
and, a2 = 3 + 2*2 = 7

So, d = a2- a1 = 2
     and, a = 5


So, S24 = 12[2a+23d] 12[2*5 + 23*2] = 12[10+46]
        S24 = 12*56  = 672

Answer 2

hope it helps you................