Help please! The graph below shows a company's profit f(x), in dollars, depending on the price of pencils x, in dollars, sold by the company:

Graph of quadratic function f of x having x intercepts at ordered pairs negative 0, 0 and 10, 0. The vertex is at 5, 160.

Part C: Describe the constraints of the domain. (3 points)

What is the value of x? enter your answer in the box. x =

Which of these statements is correct? the system of linear equations 6x - 5y = 8 and 12x - 10y = 16 has no solution. the system of linear equations 7x + 2y = 6 and 14x + 4y = 16 has an infinite number of solutions. the system of linear equations 8x - 3y = 10 and 16x - 6y = 22 has no solution. the system of linear equations 9x + 6y = 14 and 18x + 12y = 26 has an infinite number of solutions.

Which expression represents the total perimeter of her sandwich, and if x = 1.2, what is the approximate length of the crust?