Answer:
The answer is 30 
Step-by-step explanation:
If you were to do 50% of 30, it would be 15 students that are girls. There's 18 students that are girls though, so the extra 10% would make 18 students in the class girls. The remaining 40% would be 12 boys. So basically you're taking 10% from one side and putting it in the other because 50% of 30 is 15 (well this is at least how I would do it, I don't know how others would do it though)
 
        
             
        
        
        
Answer:
The answer is 58 In2
you can take apart some of the parts and multiply them, it may be easier 
 
        
             
        
        
        
Answer:
To convert a quadratic from y = ax2 + bx + c form to vertex form, y = a(x - h)2+ k, you use the process of completing the square.
Step-by-step explanation:
 
        
             
        
        
        
C because you factor it out