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Adam1994
What is the 9th term of this arithmetic sequence? 2a - b, a, b, .....
let's find the common difference between each term I guess...
the common difference is d=a-(2a-b)=b-a so we have up to the third term b 4th term b+(b-a)=2b-a 5th term 2b-a+(b-a)=3b-2a with the common difference you should be able to figure out what the nth term is. if not, just do it manually ;)