The profit P, in dollars, gained by selling X computers is modeled by the equation P+-5X^2+1000x+5000. How many computers must be sold to obtain a profit of 55,000

well, you have the formula, so just solve

-5x^2 + 1000x + 5000 = 55000
x^2 - 200x + 1000 = 0
(x-100)^2 = 0
x = 100

To find the number of computers that must be sold to obtain a profit of $55,000, we need to solve the equation P = -5X^2 + 1000X + 5000 for X.

Given that P = 55,000, we can substitute it in the equation:

55,000 = -5X^2 + 1000X + 5000

Rearranging the equation:

-5X^2 + 1000X + 5000 - 55,000 = 0

-5X^2 + 1000X - 50,000 = 0

Now, we can solve the quadratic equation. There are a few ways to solve it, but for this example, let's use the quadratic formula:

X = (-b ± √(b^2 - 4ac)) / (2a)

Using the values from our equation:

a = -5
b = 1000
c = -50,000

Plugging in these values, we get:

X = ( -1000 ± √(1000^2 - 4(-5)(-50,000))) / (2(-5))

Calculating further:

X = ( -1000 ± √(1,000,000 - 1,000,000)) / (-10)

X = ( -1000 ± √0) / (-10)

Since √0 = 0, we have:

X = ( -1000 ± 0) / (-10)

Simplifying further:

X = -1000 / -10

X = 100

Therefore, to obtain a profit of $55,000, 100 computers must be sold.

To find the number of computers that must be sold to obtain a profit of $55,000, we need to solve the equation P = 55,000.

The given equation, P = -5X^2 + 1000X + 5000, represents the profit gained by selling X computers.

Substitute the value of 55,000 for P in the equation:

55,000 = -5X^2 + 1000X + 5000

Now, we have a quadratic equation in the form of ax^2 + bx + c = 0. Rearrange the equation to set it equal to zero:

-5X^2 + 1000X + 5000 - 55,000 = 0

-5X^2 + 1000X - 50,000 = 0

To solve this quadratic equation, we can either factor it or use the quadratic formula. Factoring might not always be possible or practical, so let's use the quadratic formula:

X = (-b ± √(b^2 - 4ac)) / (2a)

For our equation -5X^2 + 1000X - 50,000 = 0, the values of a, b, and c are:
a = -5, b = 1000, and c = -50,000.

Plug these values into the quadratic formula:

X = (-(1000) ± √((1000)^2 - 4(-5)(-50,000))) / (2(-5))

Simplify the equation further:

X = (-1000 ± √(1,000,000 + 1,000,000)) / (-10)

X = (-1000 ± √2,000,000) / (-10)

X = (-1000 ± 1414.21) / (-10)

Now, we have two solutions:

X1 = (-1000 + 1414.21) / (-10)

X1 = 414.21 / (-10)

X1 = -41.42

X2 = (-1000 - 1414.21) / (-10)

X2 = -2414.21 / (-10)

X2 = 241.42

Since the number of computers cannot be negative, we discard the negative solution. Therefore, the number of computers that must be sold to obtain a profit of $55,000 is approximately 241.42, rounded to the nearest whole number.