Answer:
Number 7: 
This graph displays the change in wage per years of service. Since the slope is positive, this means the wage has a positive growth.
Number 8: 
This graph displays the amount of people evacuating per hour. Since the slope is negative, this means the amount of people evacuating per hour is reducing.
Step-by-step explanation:
Number 7:
Step 1: Identify the points on the line to use for slope formula.
The two points are (2, 11) and (6, 17).
and
will be 
and
will be 
Step 2: Plug in points into slope formula.


Step 3: Subtract.

Step 4: Simplify.
improper fraction: 
mixed number: 
decimal: 
Number 8:
Step 1: Identify the points on the line to use for the slope formula.
The two points are (3, 1200) and (6, 800)
and
will be 
and
will be 
Step 2: Plug in points into slope formula.


Step 3: Subtract.

Step 4: Simplify.
Cannot be simplified further.
mixed number: 
decimal: 