Write a possible explicit rule for each sequence, and find the 10th term.
16, 4, 1, 1/4, 1/16
I know that the recursive formula is $\displaystyle a_n = 1/4a_n-1$, but I don't know how to make an explicit formula.
A term in a geometric series is given by:
$\displaystyle T_n = ar^{n-1} $ where a is the first term, and r is the ratio between any two consecutive terms. You have already found the ratio in your recursive formula.