It's important that you use the correct symbol to indicate exponentiation.
f(x) = 0.4(3)x f(x) = 3(0.5)x f(x) = 0.8(0.9)x f(x) = 0.9(5)−x should be written as:
f(x) = 0.4(3)^x f(x) = 3(0.5)^x f(x) = 0.8(0.9)^x f(x) = 0.9(5)−x.
Please double-check that last problem, as I am unsure of whether you meant 0.9^5 or (0.9)(5).
f(x) = 0.4(3)^x is definitely an exponential function.
Please try again. Do those problems that you can do an ask questions about the others.
