Answer:
[tex]a_{n}[/tex] = - 1 [tex](-3)^{n-1}[/tex]
Step-by-step explanation:
The explicit formula for a geometric sequence is
[tex]a_{n}[/tex] = a [tex](r)^{n-1}[/tex]
where a is the first term and r the common ratio
Here a = - 1 and r = 3 ÷ - 1 = - 3 , thus explicit formula is
[tex]a_{n}[/tex] = - 1 [tex](-3)^{n-1}[/tex]
