Question

find the sum of the 24th term of an AP whose nth term is given by an =3 +2n

Answer 1

. by putting value one in the place of and we can find a one means a then put the value of 2 in the place of and then you can find a two way that you can find the difference in an ap and while putting while putting A24 you have both value A and D by putting these

Answer 2

heya it's Aastha .......

let the n be 1,2,3 .....
so,

a1 = 3+2 =5 .
a2 = 3+ 4 = 7 .
a3 = 3+ 6 =9 .

In an AP .
a = 5 , d = 2 .

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

S24 = 24 /2 { 2 ×5+ ( 24-1 ) 7 }

S24 = 672 . ..

I hope it help u .....