SOLUTION: OK, first of all the problem that I need help with is P(x)=-x^2+110x-1,000. P being 5, 50, and 120. I think that if I can get help answering the five then I should be able to figu

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: OK, first of all the problem that I need help with is P(x)=-x^2+110x-1,000. P being 5, 50, and 120. I think that if I can get help answering the five then I should be able to figu      Log On


   

Question 584959: OK, first of all the problem that I need help with is P(x)=-x^2+110x-1,000. P being 5, 50, and 120. I think that if I can get help answering the five then I should be able to figure out the 50 and the 120 (I hope). I am going to college and totally lost so if you could help me with this problem I would greatly appreciate it. I also have to graph it when I am done, but like I said earlier if I can figure out the answer to P(x)=-x^2+110x-1,000 with P being 5 I should be able to get the rest.
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
the quadratic formula will give you the solution(s)

for ax^2 + bx + c = 0 ___ x = %28-b+%2B-+sqrt%28b%5E2+-+4ac%29%29%2F%282a%29

for P = 5 ___ -x^2 + 110x - 1000 = 5 ___ -x^2 + 110x - 1005 = 0

the ± before the square root usually results in two solutions

this graph is a downward opening parabola, with the axis of symmetry at x = 55
___ the P value of the "nose" (vertex) of the parabola can be found by plugging in 55 for x