Answer:
12 
Step-by-step explanation:
4hoursx3 temp increase=12
 
        
             
        
        
        
Answer:
x > 0, if not 4/x < 0
0 < 4/x < 6/7
0 < 28/x < 6
0 < 28 < 6x
0 < 4 2/3 < x
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
b is right
Step-by-step explanation:
 
        
             
        
        
        
5b-2=13  add 2 to both sides
5b=15  divide both sides by 5
b=3
        
                    
             
        
        
        
Answer:
D not here
Step-by-step explanation:
A-2 is not reasonable as it is not possible 
C- bot possible
B- maybe
D- most reasonable