a is given to us so just plug a into the first equation:
b-3 - 3b =9 
Add 3 to both sides:
b-3b=12
Combine like terms:
-2b=12
Divide by -2 to get b by itself:
b=-6
The only answer with b as -6 is the first one, (-9,-6)
 
        
                    
             
        
        
        
Answer: (-4, -2) and (6, -2)'s slope is 0, (2,9) and (2, -5)'s is undefined
Step-by-step explanation:
bro its not that hard, y1-y2 divided by x1-x2
 
        
             
        
        
        
Answer:
534 is the mean. 
Step-by-step explanation:
 to calculate the mean you add all the numbers together (for example this set of numbers):
785, 585, 465, 409, 495, 465 
=3204 
then divide the number of numbers that you added together , (in this case 6) 
3204/6 
=
534
 
        
             
        
        
        
7-6x you are multiplying what’s in the () then comparing like term
        
                    
             
        
        
        
Answer:
yes
Step-by-step explanation:
This relation is a function
Each input value goes to only one output value so the relation is a function