This is actually really simple algebra. All you need to know is that Y= Mx + B 
and M BEING YOUR SLOPE good luck
        
                    
             
        
        
        
Answer:
A and C is true statements
 
        
                    
             
        
        
        
Lets x = Mary's age
Emily is there years older than twice her sister Mary's age = 2x + 3
Sum of both is less than 30:
x + 2x + 3 < 30
Solve for x
3x + 3 < 30
3x < 27
 x < 9
Mary's age = 9
Inequality represents Mary's possible age:
0 < x < 9
Answer is the second one
0 < x < 9
 
        
                    
             
        
        
        
Answer:
B.Arithmetic
Step-by-step explanation:
because the terms have a first common difference
the rate of change is 4