An arithmetic sequence is defined by its first term [tex]a_1[/tex]
its ratio [tex]r[/tex] and the defining formula [tex]a_n=r\times n+a_1[/tex]
The first term is given and equal [tex]a_1=-3[/tex]
The ratio is the difference between two consecutive terms, we compute like this:
[tex]a_n=a_{n-1}+7\text{ then } a_n-a_{n-1}=7\\\text{The ratio is the 7}\\\text{The rule is the :}a_n=7n-3[/tex]
The correct answer is the second one.
