Question

The sum of first 10 consecutive terms of an arithmatic sequence is 75.Its fifth term is 7. Find the sum of its first and 10th terms.find its 6th term. Find its first 3 terms.








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Answer 1

first term (a)=10

6th terms =85

so, we have

6th terms =a+5d

85=10+5d

85–10=5d

75=5d

d=15 then three terms are

first term=10

second term= 10+15=25

third term=10+2*15=40

furth term=10+3*15=55