C. The first is a solution, but the second is not.
5x - y/3 = 13 ; (2,-9) 
substitute the letters: 
5(2) - (-9/3) = 13  
10 - (-3) = 13 : note that deducting a number with a negative sign turns both sign as positive.
10 + 3 = 13 ; 
13 = 13
5x - y/3 = 13 ; (3,-6)
5(3) - (-6/3) = 13
15 - (-2) = 13
15 + 2 = 13
17 = 13 not equal. not a solution
hope i could help
        
                    
             
        
        
        
-4.75= z/2 
Multiply both sides by 2
-4.75(2)= z/2(2)
Cross out 2 and 2, divide by 1 and becomes z 
z=-9.5
Answer: z= -9.5
 
        
                    
             
        
        
        
Answer: 23
When using multiplication with brackets, you multiply the number by all the numbers within the bracket before adding them together.
Therefore when it is 8(7 + 23) it basically means: 8(7) + 8(23)
        
                    
             
        
        
        
Answer:
45.1 km^2
hope this helps
have a good day :)
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
396 : 2 * 2 * 3 * 3 * 11
Step-by-step explanation:
using long division of prime factors, you will end up with the following:
396 : 2 * 2 * 3 * 3 * 11