Question

if sum of first n term of an Ap is 5n2 -3n .find the so and also find its 16th term​

Answer 1

The given AP is 3, 5, 7, 9, 11, … <br> Its first term = 3 and common difference = (5-3) = 2. <br>

a= 3 and d = (5-3) = 2. <br> (i) Its nth term is given by <br>

<br>

<br>

<br> (ii) 16th term of the given AP is <br>

<br>

<br>

16th term = 33.