395 *25% could also be interpreted as 395/4
395 = 98.75
 4
        
                    
             
        
        
        
Answer:

Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form  or
 or  
In a proportional relationship the constant of proportionality k is equal to the slope m of the line and the line passes through the origin
In this problem we have 

Substitute the values and solve for k


therefore
the equation of the line is equal to

 
        
                    
             
        
        
        
With a 10 percent tax, you have 90 percent left. 75*.9=$67.50
        
                    
             
        
        
        
Answer:
Combined time: 55.316 seconds
The difference in times: 0.856 seconds
Tips:
It is addition and subtraction. A basic calculator should help with any other questions such as this one!