If "n+5, 2n+1, and 4n-3" are three consequtive terms in an arithmetic sequence, find n.
Let's determine a common difference by subtracting the first term from the second term.
Now determine the common difference between the 2nd and 3rd terms.
If it's truely an arithmetic sequence, these two common differences have to be equal.
Note to Anonymous1: I don't think 3 works.