Question

Find the value of 'n' if the sum of the first 'n' terms of an AP 15, 23, 31, .......... is 708 *




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Answer 1

in the given AP

D=8 (common difference)

THE FIRST TERM IS a=15

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

708 = n/2 (2×15 + (n-1)8)

1416= n (30 + 8n - 8)

1416= n (22 + 8n)

8n² + 22n - 1416=0

then factorise it and find the value of n

I hope it helps you

Answer 2

Answer:

Hey mate,

Step-by-step explanation:

The answer is provided in the above attachment.Hope it helps you dude.

Have a great day.