Arithmetic sequences have a pattern of numbers that are positive and negative but are a constant amount. 
In this case the answer is A. 
        
             
        
        
        
Answer:
54 years 
Step-by-step explanation:
Joyce age = x
Alex age = y
3x = 2y - - - (1)
y - 9 = 2(x - 9)
y - 9 = 2x - 18
-9 + 18 = 2x - y
9 = 2x - y
y = 2x - 9 - - (2)
3x = 2y
3x = 2(2x - 9)
3x = 4x - 18
18 = 4x - 3x
18 = x
Hence, 
Mrs stone is 3 * 18 = 54 years 
 
        
             
        
        
        
Answer:
175
Step-by-step explanation:
140
140/4=35
140+35=175
 
        
             
        
        
        
Answer:
5
Step-by-step explanation:
 
        
                    
             
        
        
        
D͓̽o͓̽m͓̽a͓̽i͓̽n͓̽: {-6 ≥x͓̽≤ 5}
R͓̽a͓̽n͓̽g͓̽e͓̽: {-1 ≥y͓̽≤ 4}