Question

1/9,3/9,5/9......an arithmetic sequence.find the sum of its first 9 terms?​

Answer 1

Answer:

9

Step-by-step explanation:

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

d=2/9

a=1/9

n=9

Sn=4.5(2/9 + (8)×2/9)

Sn=4.5×2/9(1+8)

Sn=4.5×2

Sn=9

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Answer 2

Answer:

9

Step-by-step explanation:

1. we find the term to term rule

  so here we subtract the second number of sequence (3/9) with the first (1/9)

here we find they add 2/9.

2. After so find the next 6 numbers following in the sequence to make it to the 9 th term.

7/9, 9/9,11/9, 13/9, 15/9 and 17

3. You then add up all the numbers 'cause it says,'find the sum of its first 9 terms?'  

when you add all of the fractions you will have 81/9 which in other numbers 9.