(trying to isolate/get x by itself in the equation)
5(x + 6) = 50      Distributive property   [distribute 5 into (x + 6)]
5x + 30 = 50    Subtraction    [subtract 30 on both sides of the equation]
5x = 20       Division     [divide 5 on both sides]
x = 4
Subtraction then division, the 2nd option
 
        
                    
             
        
        
        
The car will travel eighty miles in 1/2 hour
 
        
             
        
        
        
Constant is occurring continuously over a period of time so C is the correct answer because C is constant for a period of time  
        
                    
             
        
        
        
 A=p(1+r/100)^n
A=2500(1+4/400)^16
A=2931.45