f(x) = 5(0.8)x across the x-axis?

Question

 f(x) = 5(0.8)x across the x-axis?

Answer 1

To reflect something over the x axis you want to make outputs (your y value) that were positive negative. So if a certain x value gave positive 4 you want the new output to be negative 4. You can do that by multiplying the function by negative one. What expression would that give you here?