Question

Jamila sells knitted hats to her friends at school and she is determined that the revenue formula is R(p)=-p²+20p, where R is the revenue in dollars and p is the selling price. she wants to make $200 during her soohmore year. can she achieve this goal and what price wood she have to charge? Use quadratic formula and explain your reasonig. And how would you rewrite the equation with 200 as revenue in factored form?

Answer 1

really? You have the formula, so just solve
p^2 + 2p = 200
p^2 + 20p - 200 = 0
p = (-20±√(20^2+800))/2 = -10 ±10√3

Answer 2

oops. Missed that minus sign
-p^2 + 20p = 200
p^2 - 20p + 200 = 0
p = 10±10i
This is even worse, as it still does not factor, and there are no real solutions!

R(p) = -p^2+20p has a maximum of 100. at p=10.
So, I found my typo -- what is yours?

Answer 3

Yes really. Thanks for helping. I tried 200p=-p²+20p