Answer:
[tex]\text{\bf{C.}}\quad a_n=4+(n-1)(-7)[/tex]
Step-by-step explanation:
An arithmetic sequence that is described by the explicit formula ...
[tex]a_n=a_1+(n-1)d[/tex]
can also be described by the recursive formula ...
[tex]\left \{\begin{array}{l}a_1=\text{(first term)}&a_n=a_{n-1}+d&\end{array}\right.[/tex]
Matching parts of the formulas, we see that a1 = 4, d = -7. Putting these values into the explicit formula gives ...
[tex]a_n=4+(n-1)(-7)[/tex]
