Evaluate
14-8x-x^{2}
Factor
-\left(x-\left(-\sqrt{30}-4\right)\right)\left(x-\left(\sqrt{30}-4\right)\right)
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4-x^{2}-4x-4x+10
Multiply x and x to get x^{2}.
4-x^{2}-8x+10
Combine -4x and -4x to get -8x.
14-x^{2}-8x
Add 4 and 10 to get 14.
factor(4-x^{2}-4x-4x+10)
Multiply x and x to get x^{2}.
factor(4-x^{2}-8x+10)
Combine -4x and -4x to get -8x.
factor(14-x^{2}-8x)
Add 4 and 10 to get 14.
-x^{2}-8x+14=0
Quadratic polynomial can be factored using the transformation ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right), where x_{1} and x_{2} are the solutions of the quadratic equation ax^{2}+bx+c=0.
x=\frac{-\left(-8\right)±\sqrt{\left(-8\right)^{2}-4\left(-1\right)\times 14}}{2\left(-1\right)}
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{-\left(-8\right)±\sqrt{64-4\left(-1\right)\times 14}}{2\left(-1\right)}
Square -8.
x=\frac{-\left(-8\right)±\sqrt{64+4\times 14}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-\left(-8\right)±\sqrt{64+56}}{2\left(-1\right)}
Multiply 4 times 14.
x=\frac{-\left(-8\right)±\sqrt{120}}{2\left(-1\right)}
Add 64 to 56.
x=\frac{-\left(-8\right)±2\sqrt{30}}{2\left(-1\right)}
Take the square root of 120.
x=\frac{8±2\sqrt{30}}{2\left(-1\right)}
The opposite of -8 is 8.
x=\frac{8±2\sqrt{30}}{-2}
Multiply 2 times -1.
x=\frac{2\sqrt{30}+8}{-2}
Now solve the equation x=\frac{8±2\sqrt{30}}{-2} when ± is plus. Add 8 to 2\sqrt{30}.
x=-\left(\sqrt{30}+4\right)
Divide 8+2\sqrt{30} by -2.
x=\frac{8-2\sqrt{30}}{-2}
Now solve the equation x=\frac{8±2\sqrt{30}}{-2} when ± is minus. Subtract 2\sqrt{30} from 8.
x=\sqrt{30}-4
Divide 8-2\sqrt{30} by -2.
-x^{2}-8x+14=-\left(x-\left(-\left(\sqrt{30}+4\right)\right)\right)\left(x-\left(\sqrt{30}-4\right)\right)
Factor the original expression using ax^{2}+bx+c=a\left(x-x_{1}\right)\left(x-x_{2}\right). Substitute -\left(4+\sqrt{30}\right) for x_{1} and -4+\sqrt{30} for x_{2}.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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4 \sin \theta \cos \theta = 2 \sin \theta
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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
\lim _{x \rightarrow-3} \frac{x^{2}-9}{x^{2}+2 x-3}