we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form y=kx
where
k is the constant of proportionality
Verify each table
table a
Let
x ----> distance
y ----> sound level
For each ordered pair calculate the value of k
k=y/x
so
(5,85) -----> k=85/5=17
(10,79) ----> k=79/10=7.9
the values of k are differents
that means
the table nor represent a proportional relationship
table b
let
x ----> volume
y ----> cost
k=y/x
(16,1.49) ----> k=1.49/16=0.093125
(20,1.59) ----> k=1.59/20=0.0795
the values of k are differents
that means
the table nor represent a proportional relationship
 
        
             
        
        
        
Answer:
1/18 or 0.05
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
Leah has 80 less paychecks than the weekly person.
Step-by-step explanation:
Leah is getting 24 paychecks in 2 years, Weekly person gets 104 paychecks in 2 years, 104 - 24 = 80 paychecks.
 
        
             
        
        
        
Answer:
Part A: He spends an average of $8.50 per day
Part B:  He would save $17 per week 
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
One solution
Step-by-step explanation:
They have isolated y for you in both equations so you can plug either one into the other. 
y = 3x - 1
2x + 7 = 3x - 1
isolate the x
7 = x - 1
x = 8 
Go back to the original and plug 8 into x to get y.
y = 2 (8) + 7
y = 16 + 7
y = 23
This means at (8, 23) y = 2x+7 is equal to y = 3x-1. In other words they share a point at (8, 23). This is the only solution because for any other x and y they'd not be equal.