Answer:
A is 64 and b is 34
Step-by-step explanation:
 
        
                    
             
        
        
        
Let us say that:
K = age of Kristen
B = age of Ben
 
From the problem, we make the equations:
eqtn 1: K + B = 32
eqtn 2: (K – 4) = 2 (B – 4)
 
Simplifying eqtn 2:
K – 4 = 2 B – 8
K = 2 B – 4
 
Plugging in this to eqtn 2:
(2 B – 4) + B = 32
3 B – 4 = 32
3 B = 36
B = 12
 
From eqtn 2:
K = 2 B – 4 = 2 (12) – 4 = 20
 
So Kristen is 20 while Ben is 12.
 
        
             
        
        
        
The slope of the line is -2