6.40x+9.90(154-x)=1230.90
Solve for x
X=84 for child
154-84=70 for adults
        
             
        
        
        
There are no solutions to the given system of equations.
Hope this helps.
 
        
             
        
        
        
Cos(x) = 1 at 0 and 2pi 360 and -360 is the same angle as 2pi so all of the above if you start at 0 and make a complete circle (360) you will be back at point 0.
        
             
        
        
        
the answer is 11 hope this helps 
brainliest