Solve for x
x=-2
x=0
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2x^{2}+4x=0
Use the distributive property to multiply 2x by x+2.
x\left(2x+4\right)=0
Factor out x.
x=0 x=-2
To find equation solutions, solve x=0 and 2x+4=0.
2x^{2}+4x=0
Use the distributive property to multiply 2x by x+2.
x=\frac{-4±\sqrt{4^{2}}}{2\times 2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 2 for a, 4 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-4±4}{2\times 2}
Take the square root of 4^{2}.
x=\frac{-4±4}{4}
Multiply 2 times 2.
x=\frac{0}{4}
Now solve the equation x=\frac{-4±4}{4} when ± is plus. Add -4 to 4.
x=0
Divide 0 by 4.
x=-\frac{8}{4}
Now solve the equation x=\frac{-4±4}{4} when ± is minus. Subtract 4 from -4.
x=-2
Divide -8 by 4.
x=0 x=-2
The equation is now solved.
2x^{2}+4x=0
Use the distributive property to multiply 2x by x+2.
\frac{2x^{2}+4x}{2}=\frac{0}{2}
Divide both sides by 2.
x^{2}+\frac{4}{2}x=\frac{0}{2}
Dividing by 2 undoes the multiplication by 2.
x^{2}+2x=\frac{0}{2}
Divide 4 by 2.
x^{2}+2x=0
Divide 0 by 2.
x^{2}+2x+1^{2}=1^{2}
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=1
Square 1.
\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=0 x=-2
Subtract 1 from both sides of the equation.
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}