Choice A is one of the answers. Nice work. This is because x+x+x turns into 3x.
Choice D is the other answer because 2(x+1) + x = 2x+2+x = 3x+2. You can find this through trial and error. Or you could graph y = x+x+x+2 and y = 2(x+1)+2 to find that they are the same exact identical diagonal line. A non-graph approach would be to set up a table of values to see that the two tables are identical. 
 
        
                    
             
        
        
        
Answer:
11.65
Step-by-step explanation:
3x+99x=102x
1188/102=11.65
 
        
                    
             
        
        
        
First of all, you can simplify the 4 at the numerator and the 14 at the denominator (they're both multiple of 2):

Now, rationalize a denominator means that you have to get rid of the square root, in order to have an integer denominator. 
To do so, remember that you can always multiply any number by 1 without changing its value, and you can always think of 1 as a fraction where numerator and denominator are equal:

 
        
             
        
        
        
Answer:
Yup! Great Job!
Step-by-step explanation:
 
        
             
        
        
        
Answer: multiply by 6
Step-by-step explanation:
3×6=18
18×6=108
108×6=648