Answer:
an = an-1 *7
a1 = -3
Explanation:
We are multiplying by 7 each time
-3*7 = -21
-21 *7 = -147
The formula for a geometric sequence is
an = a1 * (r)^(n-1) where r is the common ratio and n is the term number
an = -3 ( 7) ^(n-1)
The recursive formula is
an = an-1 * r
an = an-1 *7
a1 = -3