1/4 mile per minute is the average speed.
Hi there!

We can see this by writing the factors as multipliers. We get the following:


Now we can see that the terms that are in common are 3 and a, and therefore we can bring those outside the parenthesis.
Answer:
First, find two points on the graph:
- (x₁, y₁) = (0, 2)
- (x₂, y₂) = (2, 8)
Slope = 
16 + (-3) = 16 - 3 = 13