Answer:
-2
Step-by-step explanation:
The average rate of change is the slope using the points (0, 10) and (3, 4). The slope is found using the formula 

Answer: 
Step-by-step explanation:
Given
The inequality is 
adding both side 7

Multiply both sides by 

the shaded region in the figure indicates the solution set.
Answer : 15 gallon per minute
It will cost $115 for 7 hours of music practice