It is necessary when you are getting into multiplying from the outside of parenthesis and multiplying variables inside of parenthesis. 
ex: 5(3 + 3x)
5 * 3 = 15
5 * 3x = 15x
so final set up would be 15 + 15x  
        
                    
             
        
        
        
Answer:
3
Step-by-step explanation:

 
        
             
        
        
        
Answer:
Step-by-step explanation:
5 can cancel
 
        
             
        
        
        
The possible values of  x could be -5 and -1 ithink idk
        
                    
             
        
        
        
Youll have 80 pennies. dime=.10    10x8=80