Question

The amount of revenue a company makes per day by selling x items is given by the function f(x) = 14x - 0.2x2. How many items should be sold if the company wants to maximize their profit?

Answer 1

I suppose you mean f(x) = 14x - 0.2x^2.
Please use an ^ before exponents.

The function has a maximum value where the derivative is zero.
f'(x) = 14 - 0.4 x = 0
x = 14/.4 = 35

If you don't know differential calculus yet, you can get the same result by "completing the square", but it takes longer, espcially with decimals involved.

Answer 2

Determine whether the system is consistent, inconsistent, or dependent.
3x + 2y = 15
6x + 4y = 30

Answer 3

inconsistent