Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

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