if the sum of 'n' term of an authematic progression is 3n^2+3n then common difference is
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Step-by-step explanation:
Let S
n
be the sum of n terms of an AP with first term a and common difference d.
Since S
n
=3n
2
−n and d=6
⇒S
n
=
2
n
(2a+(n−1)d)=3n
2
−n
2
n
(2a+(n−1)6)=3n
2
−n
n(a+(n−1)3)=3n
2
−n
(a+3n−3)=3n−1
a=2
hope it is helpful dear friend
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