Solve for x (complex solution)
x=\frac{5+\sqrt{71}i}{12}\approx 0.416666667+0.702179148i
x=\frac{-\sqrt{71}i+5}{12}\approx 0.416666667-0.702179148i
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-2x\times 2x+2x\times \frac{5}{2}-x\times 2x=2\times 2
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 2x, the least common multiple of 2,x.
-4xx+2x\times \frac{5}{2}-x\times 2x=2\times 2
Multiply -2 and 2 to get -4.
-4x^{2}+2x\times \frac{5}{2}-x\times 2x=2\times 2
Multiply x and x to get x^{2}.
-4x^{2}+5x-x\times 2x=2\times 2
Cancel out 2 and 2.
-4x^{2}+5x-x^{2}\times 2=2\times 2
Multiply x and x to get x^{2}.
-4x^{2}+5x-2x^{2}=2\times 2
Multiply -1 and 2 to get -2.
-6x^{2}+5x=2\times 2
Combine -4x^{2} and -2x^{2} to get -6x^{2}.
-6x^{2}+5x=4
Multiply 2 and 2 to get 4.
-6x^{2}+5x-4=0
Subtract 4 from both sides.
x=\frac{-5±\sqrt{5^{2}-4\left(-6\right)\left(-4\right)}}{2\left(-6\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -6 for a, 5 for b, and -4 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-5±\sqrt{25-4\left(-6\right)\left(-4\right)}}{2\left(-6\right)}
Square 5.
x=\frac{-5±\sqrt{25+24\left(-4\right)}}{2\left(-6\right)}
Multiply -4 times -6.
x=\frac{-5±\sqrt{25-96}}{2\left(-6\right)}
Multiply 24 times -4.
x=\frac{-5±\sqrt{-71}}{2\left(-6\right)}
Add 25 to -96.
x=\frac{-5±\sqrt{71}i}{2\left(-6\right)}
Take the square root of -71.
x=\frac{-5±\sqrt{71}i}{-12}
Multiply 2 times -6.
x=\frac{-5+\sqrt{71}i}{-12}
Now solve the equation x=\frac{-5±\sqrt{71}i}{-12} when ± is plus. Add -5 to i\sqrt{71}.
x=\frac{-\sqrt{71}i+5}{12}
Divide -5+i\sqrt{71} by -12.
x=\frac{-\sqrt{71}i-5}{-12}
Now solve the equation x=\frac{-5±\sqrt{71}i}{-12} when ± is minus. Subtract i\sqrt{71} from -5.
x=\frac{5+\sqrt{71}i}{12}
Divide -5-i\sqrt{71} by -12.
x=\frac{-\sqrt{71}i+5}{12} x=\frac{5+\sqrt{71}i}{12}
The equation is now solved.
-2x\times 2x+2x\times \frac{5}{2}-x\times 2x=2\times 2
Variable x cannot be equal to 0 since division by zero is not defined. Multiply both sides of the equation by 2x, the least common multiple of 2,x.
-4xx+2x\times \frac{5}{2}-x\times 2x=2\times 2
Multiply -2 and 2 to get -4.
-4x^{2}+2x\times \frac{5}{2}-x\times 2x=2\times 2
Multiply x and x to get x^{2}.
-4x^{2}+5x-x\times 2x=2\times 2
Cancel out 2 and 2.
-4x^{2}+5x-x^{2}\times 2=2\times 2
Multiply x and x to get x^{2}.
-4x^{2}+5x-2x^{2}=2\times 2
Multiply -1 and 2 to get -2.
-6x^{2}+5x=2\times 2
Combine -4x^{2} and -2x^{2} to get -6x^{2}.
-6x^{2}+5x=4
Multiply 2 and 2 to get 4.
\frac{-6x^{2}+5x}{-6}=\frac{4}{-6}
Divide both sides by -6.
x^{2}+\frac{5}{-6}x=\frac{4}{-6}
Dividing by -6 undoes the multiplication by -6.
x^{2}-\frac{5}{6}x=\frac{4}{-6}
Divide 5 by -6.
x^{2}-\frac{5}{6}x=-\frac{2}{3}
Reduce the fraction \frac{4}{-6} to lowest terms by extracting and canceling out 2.
x^{2}-\frac{5}{6}x+\left(-\frac{5}{12}\right)^{2}=-\frac{2}{3}+\left(-\frac{5}{12}\right)^{2}
Divide -\frac{5}{6}, the coefficient of the x term, by 2 to get -\frac{5}{12}. Then add the square of -\frac{5}{12} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{5}{6}x+\frac{25}{144}=-\frac{2}{3}+\frac{25}{144}
Square -\frac{5}{12} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{5}{6}x+\frac{25}{144}=-\frac{71}{144}
Add -\frac{2}{3} to \frac{25}{144} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{5}{12}\right)^{2}=-\frac{71}{144}
Factor x^{2}-\frac{5}{6}x+\frac{25}{144}. 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-\frac{5}{12}\right)^{2}}=\sqrt{-\frac{71}{144}}
Take the square root of both sides of the equation.
x-\frac{5}{12}=\frac{\sqrt{71}i}{12} x-\frac{5}{12}=-\frac{\sqrt{71}i}{12}
Simplify.
x=\frac{5+\sqrt{71}i}{12} x=\frac{-\sqrt{71}i+5}{12}
Add \frac{5}{12} to both sides of the equation.
Examples
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{ 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}