English, asked by pyntngenlang15, 11 months ago

find the sum up to n term of series 3×8+6×11+9×14.....nth term​

Answers

Answered by gakulgjn
1

Explanation:

3×8+6×11+9×14.......

24+66+126......n

here, a=24, d= 66-24=42, an=n

Sn= n/2(a+an)

n/2×(24+n)

24n+n²/2

some thing is wrong in the question

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