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x\left(33-x+2\right)=300
Multiply both sides of the equation by 2.
x\left(35-x\right)=300
Add 33 and 2 to get 35.
35x-x^{2}=300
Use the distributive property to multiply x by 35-x.
35x-x^{2}-300=0
Subtract 300 from both sides.
-x^{2}+35x-300=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{-35±\sqrt{35^{2}-4\left(-1\right)\left(-300\right)}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 35 for b, and -300 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-35±\sqrt{1225-4\left(-1\right)\left(-300\right)}}{2\left(-1\right)}
Square 35.
x=\frac{-35±\sqrt{1225+4\left(-300\right)}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-35±\sqrt{1225-1200}}{2\left(-1\right)}
Multiply 4 times -300.
x=\frac{-35±\sqrt{25}}{2\left(-1\right)}
Add 1225 to -1200.
x=\frac{-35±5}{2\left(-1\right)}
Take the square root of 25.
x=\frac{-35±5}{-2}
Multiply 2 times -1.
x=-\frac{30}{-2}
Now solve the equation x=\frac{-35±5}{-2} when ± is plus. Add -35 to 5.
x=15
Divide -30 by -2.
x=-\frac{40}{-2}
Now solve the equation x=\frac{-35±5}{-2} when ± is minus. Subtract 5 from -35.
x=20
Divide -40 by -2.
x=15 x=20
The equation is now solved.
x\left(33-x+2\right)=300
Multiply both sides of the equation by 2.
x\left(35-x\right)=300
Add 33 and 2 to get 35.
35x-x^{2}=300
Use the distributive property to multiply x by 35-x.
-x^{2}+35x=300
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}+35x}{-1}=\frac{300}{-1}
Divide both sides by -1.
x^{2}+\frac{35}{-1}x=\frac{300}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}-35x=\frac{300}{-1}
Divide 35 by -1.
x^{2}-35x=-300
Divide 300 by -1.
x^{2}-35x+\left(-\frac{35}{2}\right)^{2}=-300+\left(-\frac{35}{2}\right)^{2}
Divide -35, the coefficient of the x term, by 2 to get -\frac{35}{2}. Then add the square of -\frac{35}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-35x+\frac{1225}{4}=-300+\frac{1225}{4}
Square -\frac{35}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}-35x+\frac{1225}{4}=\frac{25}{4}
Add -300 to \frac{1225}{4}.
\left(x-\frac{35}{2}\right)^{2}=\frac{25}{4}
Factor x^{2}-35x+\frac{1225}{4}. 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-\frac{35}{2}\right)^{2}}=\sqrt{\frac{25}{4}}
Take the square root of both sides of the equation.
x-\frac{35}{2}=\frac{5}{2} x-\frac{35}{2}=-\frac{5}{2}
Simplify.
x=20 x=15
Add \frac{35}{2} to both sides of the equation.