Karen = x
bill = 2x - 9
total = x + 2x - 9 = 3x - 9
        
             
        
        
        
X^2 +3x-4=0
(X+4)(x-1)=0 so x = -4 and x=1 are solutions
        
                    
             
        
        
        
Math Papa is a very good calculator. You can try it. Just put the equation www.mathpapa.com :)
        
             
        
        
        
Answer:
25
Step-by-step explanation:
the question basically translates to
160% x n =40  
a little trick with percents I use is that the word "of" always means multiplication.
n=40/160%=25