Answer:
You can't get a square root of any number that has a negative sign on the inside of the radical 
 
        
             
        
        
        
2.) dT/dt = -t^2 + 3t 
dT = (-t^2 + 3t)dt 
T = -t^3/3 + 3t^2/2 + C 
at 4:00 AM 
80 = -4^3/3 + 3*4^2/2 + C 
C = 80 + 4^3/3 - 3*4^2/2 
C = 77.33 
T = -t^3/3 + 3t^2/2 + 77.33 
at 8:00 AM 
T = -8^3/3 + 3*8^2/2 + 77.33 
T = 2.67 deg
 
        
             
        
        
        
1st one : is 1/4 ( subtract 3/8 from both sides and simplify 5/8 - 3/8 to 1/4. )
2nd one : is 1/2 ( subtract 3/4 from both sides, simplify 1/4 - 3/4 to 1/-2, and then multiply both sides by -1 )
3rd one : is 5/6 ( subtract 1/8 from both sides and simplify 23/24 - 1/8 to 5/6).
        
                    
             
        
        
        
Alex has $14, Barry has $12 and Carl has $9
 
        
             
        
        
        
It is 27 you add 10 and 27 which equals 27.