I believe the answer is C
Exponential Function.

Also the shown graph is a decreasing graph.

The equation above is the equation of the graph that is shown in the picture.
Answer: 
Step-by-step explanation:
Given the following equation:

You can follow these steps in order to solve for "x" and find its value:
1. Apply Distributive property on the right side of the equation:

2. Subract
from both sides and add the like terms:

3. Subtract 1.8 from both sides:

4. Finally, divide both side of the equation by -1.5:
