We know that this is an arithmetic sequence, because we have a common difference of 2.
Thus, we can generalise this to become an arithmetic sequence:
[tex]T_n = a + (n - 1)d[/tex], where a is the first term, n is the nth term, and d is the common difference.
Thus, by substituting everything in, we get:
[tex]T_n = 3 + (n - 1)2[/tex]
[tex]T_n = 3 + 2n - 2[/tex]
[tex]T_n = 1 + 2n[/tex]
Our equation becomes: [tex]y = 1 + 2x[/tex]
