Answer:
The diameter is 2 times the radius.
D=2r
Substitute 20 as the diameter and solve for r.
20=2r
Divide both sides by 2.
10=r
So, the radius is 10 centimeters.
:)
Answer:
The best estimate for the average rate of change is 
Step-by-step explanation:
we know that
the average rate of change using the graph is equal to
In this problem we have
Substitute