Solve for x
x = \frac{3 \sqrt{17} + 9}{4} \approx 5.342329219
x=\frac{9-3\sqrt{17}}{4}\approx -0.842329219
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Quadratic Equation
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4 \times ( x + 3 ) - 2 x ( x - 1 ) = 3 x - 3 ( 2 x - 1 )
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4x+12-2x\left(x-1\right)=3x-3\left(2x-1\right)
Use the distributive property to multiply 4 by x+3.
4x+12-2x\left(x-1\right)=3x-6x+3
Use the distributive property to multiply -3 by 2x-1.
4x+12-2x\left(x-1\right)=-3x+3
Combine 3x and -6x to get -3x.
4x+12-2x\left(x-1\right)+3x=3
Add 3x to both sides.
4x+12-2x\left(x-1\right)+3x-3=0
Subtract 3 from both sides.
4x+12-2x^{2}+2x+3x-3=0
Use the distributive property to multiply -2x by x-1.
6x+12-2x^{2}+3x-3=0
Combine 4x and 2x to get 6x.
9x+12-2x^{2}-3=0
Combine 6x and 3x to get 9x.
9x+9-2x^{2}=0
Subtract 3 from 12 to get 9.
-2x^{2}+9x+9=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{-9±\sqrt{9^{2}-4\left(-2\right)\times 9}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, 9 for b, and 9 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-9±\sqrt{81-4\left(-2\right)\times 9}}{2\left(-2\right)}
Square 9.
x=\frac{-9±\sqrt{81+8\times 9}}{2\left(-2\right)}
Multiply -4 times -2.
x=\frac{-9±\sqrt{81+72}}{2\left(-2\right)}
Multiply 8 times 9.
x=\frac{-9±\sqrt{153}}{2\left(-2\right)}
Add 81 to 72.
x=\frac{-9±3\sqrt{17}}{2\left(-2\right)}
Take the square root of 153.
x=\frac{-9±3\sqrt{17}}{-4}
Multiply 2 times -2.
x=\frac{3\sqrt{17}-9}{-4}
Now solve the equation x=\frac{-9±3\sqrt{17}}{-4} when ± is plus. Add -9 to 3\sqrt{17}.
x=\frac{9-3\sqrt{17}}{4}
Divide -9+3\sqrt{17} by -4.
x=\frac{-3\sqrt{17}-9}{-4}
Now solve the equation x=\frac{-9±3\sqrt{17}}{-4} when ± is minus. Subtract 3\sqrt{17} from -9.
x=\frac{3\sqrt{17}+9}{4}
Divide -9-3\sqrt{17} by -4.
x=\frac{9-3\sqrt{17}}{4} x=\frac{3\sqrt{17}+9}{4}
The equation is now solved.
4x+12-2x\left(x-1\right)=3x-3\left(2x-1\right)
Use the distributive property to multiply 4 by x+3.
4x+12-2x\left(x-1\right)=3x-6x+3
Use the distributive property to multiply -3 by 2x-1.
4x+12-2x\left(x-1\right)=-3x+3
Combine 3x and -6x to get -3x.
4x+12-2x\left(x-1\right)+3x=3
Add 3x to both sides.
4x+12-2x^{2}+2x+3x=3
Use the distributive property to multiply -2x by x-1.
6x+12-2x^{2}+3x=3
Combine 4x and 2x to get 6x.
9x+12-2x^{2}=3
Combine 6x and 3x to get 9x.
9x-2x^{2}=3-12
Subtract 12 from both sides.
9x-2x^{2}=-9
Subtract 12 from 3 to get -9.
-2x^{2}+9x=-9
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}+9x}{-2}=-\frac{9}{-2}
Divide both sides by -2.
x^{2}+\frac{9}{-2}x=-\frac{9}{-2}
Dividing by -2 undoes the multiplication by -2.
x^{2}-\frac{9}{2}x=-\frac{9}{-2}
Divide 9 by -2.
x^{2}-\frac{9}{2}x=\frac{9}{2}
Divide -9 by -2.
x^{2}-\frac{9}{2}x+\left(-\frac{9}{4}\right)^{2}=\frac{9}{2}+\left(-\frac{9}{4}\right)^{2}
Divide -\frac{9}{2}, the coefficient of the x term, by 2 to get -\frac{9}{4}. Then add the square of -\frac{9}{4} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{9}{2}x+\frac{81}{16}=\frac{9}{2}+\frac{81}{16}
Square -\frac{9}{4} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{9}{2}x+\frac{81}{16}=\frac{153}{16}
Add \frac{9}{2} to \frac{81}{16} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{9}{4}\right)^{2}=\frac{153}{16}
Factor x^{2}-\frac{9}{2}x+\frac{81}{16}. 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{9}{4}\right)^{2}}=\sqrt{\frac{153}{16}}
Take the square root of both sides of the equation.
x-\frac{9}{4}=\frac{3\sqrt{17}}{4} x-\frac{9}{4}=-\frac{3\sqrt{17}}{4}
Simplify.
x=\frac{3\sqrt{17}+9}{4} x=\frac{9-3\sqrt{17}}{4}
Add \frac{9}{4} to 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}