Do you want to solve for x and y?
What is the objective?
        
             
        
        
        
Answer:
y= -4x+22
Step-by-step explanation:
slope= -4
-6=-4(7)+b
-4x7=-28
-6=-28+b
28-6=22
so the equation would be y= -4x+22
b=y-intercept
mx=slope multiplied by x
 
        
             
        
        
        
Answer:
y = 1/2x - 2
Step-by-step explanation:
use formula y = mx + c 
m = gradient 
c = y intercept 
 
        
             
        
        
        
Under Daily flat rate, we would have 22 and 0.15x
Under Cost per mile, we would have 0.15
Under Number of Miles Driven, we would have x