Please need help on these two

Answer:
1. The multiplicative rate of change is 4.
2. (2,20)
Step-by-step explanation:
The formula for this exponential function would be f(x) = A • B^x. A is the initial amount, and B is the rate of growth, or the multiplicative rate of change. For number two, if you plug in the numbers they give you, you can see that when x is 2, f(x) is 50. Therefore, it cannot be (2, 20).