Solve for x
x=4
x=146
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150x-x^{2}=0.1168\times 100\times 50
Subtract 0.8832 from 1 to get 0.1168.
150x-x^{2}=11.68\times 50
Multiply 0.1168 and 100 to get 11.68.
150x-x^{2}=584
Multiply 11.68 and 50 to get 584.
150x-x^{2}-584=0
Subtract 584 from both sides.
-x^{2}+150x-584=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=150 ab=-\left(-584\right)=584
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as -x^{2}+ax+bx-584. To find a and b, set up a system to be solved.
1,584 2,292 4,146 8,73
Since ab is positive, a and b have the same sign. Since a+b is positive, a and b are both positive. List all such integer pairs that give product 584.
1+584=585 2+292=294 4+146=150 8+73=81
Calculate the sum for each pair.
a=146 b=4
The solution is the pair that gives sum 150.
\left(-x^{2}+146x\right)+\left(4x-584\right)
Rewrite -x^{2}+150x-584 as \left(-x^{2}+146x\right)+\left(4x-584\right).
-x\left(x-146\right)+4\left(x-146\right)
Factor out -x in the first and 4 in the second group.
\left(x-146\right)\left(-x+4\right)
Factor out common term x-146 by using distributive property.
x=146 x=4
To find equation solutions, solve x-146=0 and -x+4=0.
150x-x^{2}=0.1168\times 100\times 50
Subtract 0.8832 from 1 to get 0.1168.
150x-x^{2}=11.68\times 50
Multiply 0.1168 and 100 to get 11.68.
150x-x^{2}=584
Multiply 11.68 and 50 to get 584.
150x-x^{2}-584=0
Subtract 584 from both sides.
-x^{2}+150x-584=0
All equations of the form ax^{2}+bx+c=0 can be solved using the quadratic formula: \frac{-b±\sqrt{b^{2}-4ac}}{2a}. The quadratic formula gives two solutions, one when ± is addition and one when it is subtraction.
x=\frac{-150±\sqrt{150^{2}-4\left(-1\right)\left(-584\right)}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 150 for b, and -584 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-150±\sqrt{22500-4\left(-1\right)\left(-584\right)}}{2\left(-1\right)}
Square 150.
x=\frac{-150±\sqrt{22500+4\left(-584\right)}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-150±\sqrt{22500-2336}}{2\left(-1\right)}
Multiply 4 times -584.
x=\frac{-150±\sqrt{20164}}{2\left(-1\right)}
Add 22500 to -2336.
x=\frac{-150±142}{2\left(-1\right)}
Take the square root of 20164.
x=\frac{-150±142}{-2}
Multiply 2 times -1.
x=-\frac{8}{-2}
Now solve the equation x=\frac{-150±142}{-2} when ± is plus. Add -150 to 142.
x=4
Divide -8 by -2.
x=-\frac{292}{-2}
Now solve the equation x=\frac{-150±142}{-2} when ± is minus. Subtract 142 from -150.
x=146
Divide -292 by -2.
x=4 x=146
The equation is now solved.
150x-x^{2}=0.1168\times 100\times 50
Subtract 0.8832 from 1 to get 0.1168.
150x-x^{2}=11.68\times 50
Multiply 0.1168 and 100 to get 11.68.
150x-x^{2}=584
Multiply 11.68 and 50 to get 584.
-x^{2}+150x=584
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
\frac{-x^{2}+150x}{-1}=\frac{584}{-1}
Divide both sides by -1.
x^{2}+\frac{150}{-1}x=\frac{584}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}-150x=\frac{584}{-1}
Divide 150 by -1.
x^{2}-150x=-584
Divide 584 by -1.
x^{2}-150x+\left(-75\right)^{2}=-584+\left(-75\right)^{2}
Divide -150, the coefficient of the x term, by 2 to get -75. Then add the square of -75 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-150x+5625=-584+5625
Square -75.
x^{2}-150x+5625=5041
Add -584 to 5625.
\left(x-75\right)^{2}=5041
Factor x^{2}-150x+5625. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(x-75\right)^{2}}=\sqrt{5041}
Take the square root of both sides of the equation.
x-75=71 x-75=-71
Simplify.
x=146 x=4
Add 75 to both sides of the equation.
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