Q4 of 28 Page 9

If nth term of an A.P. is 6n – 7 then write its common difference.

We know an = a+(n-1)d


⇒ 6n – 7 = a+(n-1)d


⇒ 6n – 7 = a + nd – d


⇒ 6n – 7 = a – d + nd


Comparing the coefficients, we get,


6n = nd


d = 6


hence common difference is 6.


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