Answer:
g(x) = f(5x)
Explanation:
We assume that "shrink by a factor of 1/5" means that horizontal distances on the graph of g(x) are 1/5 of those on the graph of f(x).
Dividing x by a dilation factor will cause horizontal dilation of a graph. Here, that factor is 1/5, so the desired function is ...
g(x) = f(x/(1/5))
g(x) = f(5x)