Question

the sum of 15 terms of an arithmetic sequence with common difference 6 is 780.write the algebric expression of the sequence
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Answer 1

Answer:

Step-by-step explanation:

Sum of terms in AP=n/2(2a+(n-1)d)

780=15/2(2a+14*6)

780=15(a+42)

780/15=a+42

a=52-42

a=10

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Answer 2

Answer:

https://brainly.in/question/19975681

Step-by-step explanation: