Evaluate
2x^{2}-4xy-y^{2}
Factor
2x^{2}-4xy-y^{2}
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2\left(x-\frac{\left(2+\sqrt{6}\right)y}{2}\right)\left(x-\frac{2-\sqrt{6}}{2}y\right)
Express \frac{2+\sqrt{6}}{2}y as a single fraction.
2\left(x-\frac{2y+\sqrt{6}y}{2}\right)\left(x-\frac{2-\sqrt{6}}{2}y\right)
Use the distributive property to multiply 2+\sqrt{6} by y.
2\left(\frac{2x}{2}-\frac{2y+\sqrt{6}y}{2}\right)\left(x-\frac{2-\sqrt{6}}{2}y\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply x times \frac{2}{2}.
2\times \frac{2x-\left(2y+\sqrt{6}y\right)}{2}\left(x-\frac{2-\sqrt{6}}{2}y\right)
Since \frac{2x}{2} and \frac{2y+\sqrt{6}y}{2} have the same denominator, subtract them by subtracting their numerators.
2\times \frac{2x-2y-\sqrt{6}y}{2}\left(x-\frac{2-\sqrt{6}}{2}y\right)
Do the multiplications in 2x-\left(2y+\sqrt{6}y\right).
2\times \frac{2x-2y-\sqrt{6}y}{2}\left(x-\frac{\left(2-\sqrt{6}\right)y}{2}\right)
Express \frac{2-\sqrt{6}}{2}y as a single fraction.
2\times \frac{2x-2y-\sqrt{6}y}{2}\left(x-\frac{2y-\sqrt{6}y}{2}\right)
Use the distributive property to multiply 2-\sqrt{6} by y.
2\times \frac{2x-2y-\sqrt{6}y}{2}\left(\frac{2x}{2}-\frac{2y-\sqrt{6}y}{2}\right)
To add or subtract expressions, expand them to make their denominators the same. Multiply x times \frac{2}{2}.
2\times \frac{2x-2y-\sqrt{6}y}{2}\times \frac{2x-\left(2y-\sqrt{6}y\right)}{2}
Since \frac{2x}{2} and \frac{2y-\sqrt{6}y}{2} have the same denominator, subtract them by subtracting their numerators.
2\times \frac{2x-2y-\sqrt{6}y}{2}\times \frac{2x-2y+\sqrt{6}y}{2}
Do the multiplications in 2x-\left(2y-\sqrt{6}y\right).
\left(2x-2y-\sqrt{6}y\right)\times \frac{2x-2y+\sqrt{6}y}{2}
Cancel out 2 and 2.
\frac{\left(2x-2y-\sqrt{6}y\right)\left(2x-2y+\sqrt{6}y\right)}{2}
Express \left(2x-2y-\sqrt{6}y\right)\times \frac{2x-2y+\sqrt{6}y}{2} as a single fraction.
\frac{4x^{2}-4xy+2x\sqrt{6}y-4xy+4y^{2}-2\sqrt{6}y^{2}-2\sqrt{6}yx+2\sqrt{6}y^{2}-\left(\sqrt{6}\right)^{2}y^{2}}{2}
Apply the distributive property by multiplying each term of 2x-2y-\sqrt{6}y by each term of 2x-2y+\sqrt{6}y.
\frac{4x^{2}-8xy+2x\sqrt{6}y+4y^{2}-2\sqrt{6}y^{2}-2\sqrt{6}yx+2\sqrt{6}y^{2}-\left(\sqrt{6}\right)^{2}y^{2}}{2}
Combine -4xy and -4xy to get -8xy.
\frac{4x^{2}-8xy+4y^{2}-2\sqrt{6}y^{2}+2\sqrt{6}y^{2}-\left(\sqrt{6}\right)^{2}y^{2}}{2}
Combine 2x\sqrt{6}y and -2\sqrt{6}yx to get 0.
\frac{4x^{2}-8xy+4y^{2}-\left(\sqrt{6}\right)^{2}y^{2}}{2}
Combine -2\sqrt{6}y^{2} and 2\sqrt{6}y^{2} to get 0.
\frac{4x^{2}-8xy+4y^{2}-6y^{2}}{2}
The square of \sqrt{6} is 6.
\frac{4x^{2}-8xy-2y^{2}}{2}
Combine 4y^{2} and -6y^{2} to get -2y^{2}.
2x^{2}-4xy-y^{2}
Divide each term of 4x^{2}-8xy-2y^{2} by 2 to get 2x^{2}-4xy-y^{2}.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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y = 3x + 4
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Matrix
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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
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