how many dresses must alice sell in order to make a profit of 600 $?

Question

The profit of alices dresshop is given by the equation P=x^2 + 20x - 200 where x is the number of dresses sold. how many dresses must alice sell in order to make a profit of 600 $?

Answer 1

600 = X^2 + 20X -200
0 = X^2 +20X -800
0 = (X + 40)(X - 20)
X = 40 - 20
X = 20

She needs to sell 20 dresses.

Answer 2

Simply set P = 600

x^2 + 20x - 200 = 600

Subtract 600 from each side to put the equation in standard form

x^2 + 20x - 800 = 0

Now use the quadratic formula to solve for x


By the way, normally the squared term is negative, representing the fact that as prices rise, purchases drop off dramatically.

Answer 3

ok. so if the profit is $600, then the equation will look like this: 600=x^2+20x-200
subtract 600 from each side
0=x^2+20x-800
the you FOIL (first outer inner last)
(x-20)(x+40)=0
then solve each of those seperatly...
x=20 and x=-40 but since she cant sell -40 dresses, the answer is 20 dresses.

Answer 4

You set P= 600 and you solve for x getting ( x -20)(x+40)
so x = 20 or -40 and since you can't sell -40 dresses the answer must be 20

Answer 5

Put 600 into that equation where P is.

Then make one side equal to zero, by subtracting 600 from both sides.

Then do the quadratic equation. A is 1 (because that's the integer in front of x^2), B is 20, and C is -800.

Quadratics pop up two answers, one positive and one negative. Obviously, you want the positive answer.

Answer 6

20 dresses

20 x 20 = 400
400 + (20 x 20) =
400 + 400 = 800
800 - 200 = $600

Answer 7

23

Answer 8

600 = x^2 + 20x -200

x^2 + 20x -800 =0

(x + 40) (x-20) = 0
x = 20

Answer 9

20 dresses

Answer 10

She would have to sell 60 dresses