The profit P(x) of a cosmetics company, in thousands of dollars, is given by 𝑃(𝑥) = −5𝑥2 + 400𝑥 +2500, where x is the amount spent on advertising in thousands of dollars. What amount must be spent on advertising to obtain a profit of at least $4 000 000?

Answer 1

clearly, you just have to solve
−5x^2 + 400x +2500 ≥ 4000
so crank 'er out. Post your work if you get stuck.

Answer 2

I need help