we know taht
the explicit formula for an arithmetic sequence is equal to
[tex]a_n=a_1+d(n-1)[/tex]
In this problem we have that
[tex]a_n=-7+6n[/tex]
we know that
the distance betwee consecutive numbers is 6
that means
the common difference is d=6
substitute the value of d in the first equation
[tex]\begin{gathered} a_n=a_1+6(n-1) \\ a_n=a_1+6n-6 \end{gathered}[/tex]
Equete both equations
