C(x) = 300. 
Our question becomes simple: 300 = x^2-40x+610
x^2-40x+610-300 = 0
x^2-40x+310 = 0
Now find the value for x with either the quadratic formula or by factorization.
Let me know how it goes. Giving the full answer won’t help you improve
        
                    
             
        
        
        
Answer:
In the first step, there is an issue when distributing the -3 to the terms inside of the parentheses. When multiplying the -3 to the -5, you would get an answer of +15, not -15.
The full correct process is:
(4m + 9) - 3(2m - 5) = 4m + 9 - 6m + 15
                                 = 4m - 6m + 9 + 15
                                 = -2m + 24
 
        
             
        
        
        
Answer:

Step-by-step explanation:

 
        
             
        
        
        
Answer:
.9
Step-by-step explanation:
 
        
                    
             
        
        
        
Move X to the other side with the 30.