Solve for x
x=1
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4x-2-2x^{2}=0
Subtract 2x^{2} from both sides.
2x-1-x^{2}=0
Divide both sides by 2.
-x^{2}+2x-1=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=2 ab=-\left(-1\right)=1
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as -x^{2}+ax+bx-1. To find a and b, set up a system to be solved.
a=1 b=1
Since ab is positive, a and b have the same sign. Since a+b is positive, a and b are both positive. The only such pair is the system solution.
\left(-x^{2}+x\right)+\left(x-1\right)
Rewrite -x^{2}+2x-1 as \left(-x^{2}+x\right)+\left(x-1\right).
-x\left(x-1\right)+x-1
Factor out -x in -x^{2}+x.
\left(x-1\right)\left(-x+1\right)
Factor out common term x-1 by using distributive property.
x=1 x=1
To find equation solutions, solve x-1=0 and -x+1=0.
4x-2-2x^{2}=0
Subtract 2x^{2} from both sides.
-2x^{2}+4x-2=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{-4±\sqrt{4^{2}-4\left(-2\right)\left(-2\right)}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, 4 for b, and -2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-4±\sqrt{16-4\left(-2\right)\left(-2\right)}}{2\left(-2\right)}
Square 4.
x=\frac{-4±\sqrt{16+8\left(-2\right)}}{2\left(-2\right)}
Multiply -4 times -2.
x=\frac{-4±\sqrt{16-16}}{2\left(-2\right)}
Multiply 8 times -2.
x=\frac{-4±\sqrt{0}}{2\left(-2\right)}
Add 16 to -16.
x=-\frac{4}{2\left(-2\right)}
Take the square root of 0.
x=-\frac{4}{-4}
Multiply 2 times -2.
x=1
Divide -4 by -4.
4x-2-2x^{2}=0
Subtract 2x^{2} from both sides.
4x-2x^{2}=2
Add 2 to both sides. Anything plus zero gives itself.
-2x^{2}+4x=2
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{-2x^{2}+4x}{-2}=\frac{2}{-2}
Divide both sides by -2.
x^{2}+\frac{4}{-2}x=\frac{2}{-2}
Dividing by -2 undoes the multiplication by -2.
x^{2}-2x=\frac{2}{-2}
Divide 4 by -2.
x^{2}-2x=-1
Divide 2 by -2.
x^{2}-2x+1=-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.
x^{2}-2x+1=0
Add -1 to 1.
\left(x-1\right)^{2}=0
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{0}
Take the square root of both sides of the equation.
x-1=0 x-1=0
Simplify.
x=1 x=1
Add 1 to both sides of the equation.
x=1
The equation is now solved. Solutions are the same.
Examples
Quadratic equation
{ x } ^ { 2 } - 4 x - 5 = 0
Trigonometry
4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
Matrix
\left[ \begin{array} { l l } { 2 } & { 3 } \\ { 5 } & { 4 } \end{array} \right] \left[ \begin{array} { l l l } { 2 } & { 0 } & { 3 } \\ { -1 } & { 1 } & { 5 } \end{array} \right]
Simultaneous equation
\left. \begin{cases} { 8x+2y = 46 } \\ { 7x+3y = 47 } \end{cases} \right.
Differentiation
\frac { d } { d x } \frac { ( 3 x ^ { 2 } - 2 ) } { ( x - 5 ) }
Integration
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}