When you divide fractions, you change each to its reciprocal, then you look multiply them. Using reciprocals helps you easily solve the problem.
        
             
        
        
        
Answer:
No entiendo por qué está en ingles
 
        
             
        
        
        
Answer:
13 (i think)
Step-by-step explanation:
 
        
                    
             
        
        
        
Solving for variables in equations is important for many reasons.  Of course, it's important to be able to solve for them so you can pass math tests.  But even more so, it's important for real-life applications.  There are many uses for solving equations.  They can provide answers for mathematicians, accountants, insurance companies- you name it!  There are way too many to list!  It may not seem important now, but just keep working at it!  I personally think solving equations is a ton of fun!
        
             
        
        
        
Find rates of change until you find a constant.
dy/dx=1,2,3,4,5,6
d2y/dx2=1,1,1,1,1  
So the acceleration, d2y/d2x, is constant.  This means that this is a quadratic sequence of the form a(n)=an^2+bn+c.  So we can set up a system of equations to solve for the values of a,b, and c.  Using the first three points, (1,1), (2,2), and (3,4) we have:
9a+3b+c=4, 4a+2b+c=2, and a+b+c=1  getting the differences...
5a+b=2 and 3a+b=1  and getting this difference...
2a=1, so a=1/2 making 5a+b=2 become:
2.5+b=2, so b=-1/2, making a+b+c=1 become:
1/2-1/2+c=1, so c=1  so the rule is:
a(n)=0.5x^2-0.5x+1  or if you prefer to not have decimals
a(n)=(x^2-x+2)/2