I think the answer is 30 square units
Total Cost in a day is

. Profit function is

. And the revenue function is

. In a day, bookstore must sell at least 15 books, because of 6n-90=0, in order to make profit.
The answer to this question is 23
Answer:


Step-by-step explanation:
Given system of equations:

To solve by the method of substitution, substitute the first equation into the second equation and rearrange so that the equation equals zero:

Factor the quadratic:

Apply the <u>zero-product property</u> and solve for x:


Substitute the found values of x into the <u>second equation</u> and solve for y:


Therefore, the solutions are:


Answer:

Step-by-step explanation:
Midpoint formula is
---------------(1)
Here

Substituting values in equation (1)

