Which function represents a reflection of f(x) = 5(0.8)x across the x-axis?
g(x) = 5(0.8)–x
g(x) = –5(0.8)x
g(x) = (0.8)x
g(x) = 5(–0.8)x

The function f(x) = 5(0.8)x is located in the first quadrant, forming a increasing curve. Imagine the reflection of the graph of the function. It is located in the fourth quadrant, forming a decreasing curve.

The graph that shows reflection is just the negative of the function. So the answer is (x) = –5(0.8)x