It is c because it adds 6 and minuses 2
        
             
        
        
        
Answer:
Step-by-step explanation:
 
        
             
        
        
        
Let x be the number of times they raise the price on the newspaper. Then the new cost of the newspaper is 

Let y be the newspaper they sell, then the income will be 

Now, we know that the circulation is of 500, assuming that they sold every newspaper at the original price now the number the will sell will be 

Plugging the value of y in the first expression we have that the income will be 

Then the income is given by the function 

To find the maximum value of this functions (thus the maximum income) we need to take the derivative of the function, 

no we equate the derivative to zero and solve for x.

This means that we have an extreme value of the function when x=9. Now we need to find out if this value is a maximum or a minimum. To do this we need to take the second derivative of the function, then

Since the second derivative is negative in the point x=9, we conclude that this value is a maximum of the function. 
With this we conclude that the number of times that they should raise the price to maximize the income is 9. This means that they will raise the price of the newspaper (9)($0.05)=$0.45.
Therefore the price to maximize the income is $0.35+$0.45=$0.80.
 
        
             
        
        
        
Answer:

Step-by-step explanation:
The distributive law states that 

The expression 3+21a+15b consists of three terms:
- 3=3·1;
- 21a=3·7a;
- 15b=3·5b.
You can see that 3 is the common factor of these three terms, thus

 
        
             
        
        
        
Answer:
385
Step-by-step explanation:
260 divided by 4 =65
65 + 65 + 260= 385