Question

Q---If sum of the first q terms of an AP is 2q+3q2. what is its common difference?

Answer 1

see...
here is the answer....
sum of first term =a
S1=2*1+3*1^2
=2+3=5
now,
sum of first two terms,
S2=2*2+3*2^2
=16
SECOND TERM=S2-S1
=16-5
=11
COMMON DIFFERENCE=11-5=6
hope it is correct....
plz.... tell if it is correct or not

Answer 2

Answer :-

Given sum of first q terms, Sq = 2q + 3q²

Put q = 1, we get S1 = 2 + 3 = 5

Put q = 2, we get S2 = 2(2) + 3(2)2 = 4 + 12 = 16

Here first term a or t1 = 5

t2 = S2 – S1

= 16 – 5 = 11

Common difference, d = t2 – t1

= 11 – 5 = 6

Hence the common difference is 6

___________[Answer]

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6 is the common difference.