Which function below represents exponential decay?
ƒ(x) = 0.5(2)x
ƒ(x) = 4(0.25)x
ƒ(x) = 2(1.3)x
ƒ(x) = (-3)x
ƒ(x) = 0.5(2)x
ƒ(x) = 4(0.25)x
ƒ(x) = 2(1.3)x
ƒ(x) = (-3)x