Question

if the sum of number of terms of an A.P is 3n² +3n then common diffrence is​

Answer 1

Step-by-step explanation:

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

3n²+3n = n/2 ( 2a + (n-1)d)

6n² + 6n = n(2a+(n-1)d)

6n+6 = 2a+(n-1)d ( let a = 1)

6n + 6 = 2 + (n-1)d

6n +4 = (n-1)d

d = 6n+4/n-1....;):)