Answer:
The system of equations has one solution. The two equations are intersecting lines.
Step-by-step explanation:
if you want to use the substitution method, you would have to plug in y for 12x+2 in the second equation. 
2(12x+2)=x+4
next, you have to distribute
24x+4=x+4
subtract 24x from each side
4=-23x+4
subtract 4 from each side
0=23x
divide each side by 23
x=0
now, plug in 0 to one equation. 
y=12(0)+2
y=2
the lines intersect at one point, (0,2)
 
        
             
        
        
        
Average speed = 24 3/4 / 1 1/2 = 99/4 / 3/2 = 99/4 x 2/3 = 16 1/2 miles per hour.
        
                    
             
        
        
        
Answer: B
Step-by-step explanation:
Well if it's a greater than statement you can rule out C and D because those are less than symbols ( > = Less,  < = Greater) It can't be A because thats his starting amount. The x means how many months it will take for him to get more than 70 stamps