math
posted by stacii .
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?

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