Answer:
12 times 2 since it doubles every time I'm not that sure so if I am not correct my bads
 
        
             
        
        
        
Answer:
The solutions are: 
 
     
Step-by-step explanation:
We have the following quadratic equation

We can rewrite the equation as follows

Now we use the quadratic formula to solve the equation
For an equation of the form  the quadratic formula is:
 the quadratic formula is:

In this case:

Then:





 
        
                    
             
        
        
        
First, distribute the 100 to the (x-1) portion:
500 = 100x - 100
then, add 100 to both sides of your equation to get “x” alone on the right side:
500 + 100 = 100x - 100 + 100
600 = 100x
next, divide 100x by 100 and 600 by 100 to isolate a singular “x”:
600/100 = 100x/100
6 = x
therefore, x=6 is your solution
        
             
        
        
        
You can only do it like '7.5 plus 9.5 plus 13