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x-\frac{1}{4}x^{2}=0
Subtract \frac{1}{4}x^{2} from both sides.
x\left(1-\frac{1}{4}x\right)=0
Factor out x.
x=0 x=4
To find equation solutions, solve x=0 and 1-\frac{x}{4}=0.
x-\frac{1}{4}x^{2}=0
Subtract \frac{1}{4}x^{2} from both sides.
-\frac{1}{4}x^{2}+x=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{-1±\sqrt{1^{2}}}{2\left(-\frac{1}{4}\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -\frac{1}{4} for a, 1 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-1±1}{2\left(-\frac{1}{4}\right)}
Take the square root of 1^{2}.
x=\frac{-1±1}{-\frac{1}{2}}
Multiply 2 times -\frac{1}{4}.
x=\frac{0}{-\frac{1}{2}}
Now solve the equation x=\frac{-1±1}{-\frac{1}{2}} when ± is plus. Add -1 to 1.
x=0
Divide 0 by -\frac{1}{2} by multiplying 0 by the reciprocal of -\frac{1}{2}.
x=-\frac{2}{-\frac{1}{2}}
Now solve the equation x=\frac{-1±1}{-\frac{1}{2}} when ± is minus. Subtract 1 from -1.
x=4
Divide -2 by -\frac{1}{2} by multiplying -2 by the reciprocal of -\frac{1}{2}.
x=0 x=4
The equation is now solved.
x-\frac{1}{4}x^{2}=0
Subtract \frac{1}{4}x^{2} from both sides.
-\frac{1}{4}x^{2}+x=0
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{-\frac{1}{4}x^{2}+x}{-\frac{1}{4}}=\frac{0}{-\frac{1}{4}}
Multiply both sides by -4.
x^{2}+\frac{1}{-\frac{1}{4}}x=\frac{0}{-\frac{1}{4}}
Dividing by -\frac{1}{4} undoes the multiplication by -\frac{1}{4}.
x^{2}-4x=\frac{0}{-\frac{1}{4}}
Divide 1 by -\frac{1}{4} by multiplying 1 by the reciprocal of -\frac{1}{4}.
x^{2}-4x=0
Divide 0 by -\frac{1}{4} by multiplying 0 by the reciprocal of -\frac{1}{4}.
x^{2}-4x+\left(-2\right)^{2}=\left(-2\right)^{2}
Divide -4, the coefficient of the x term, by 2 to get -2. Then add the square of -2 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-4x+4=4
Square -2.
\left(x-2\right)^{2}=4
Factor x^{2}-4x+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-2\right)^{2}}=\sqrt{4}
Take the square root of both sides of the equation.
x-2=2 x-2=-2
Simplify.
x=4 x=0
Add 2 to both sides of the equation.