Answer:
[tex]an = 2.5 + (n - 1)(-5)[/tex]
Step-by-step explanation:
we know that
The explicit formula for the nth term of an arithmetic sequence is given by the formula
[tex]an = a1 + (n - 1)r[/tex]
where
a1 is the first term
n is the term number
r is the common difference
In this problem we have
[tex]a1=2.5, r=-5[/tex]
substitute
[tex]an = 2.5 + (n - 1)(-5)[/tex]