Solve for x
x=\sqrt{5}+2\approx 4.236067977
x=2-\sqrt{5}\approx -0.236067977
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2\left(3x+1\right)=x\times 2\left(x-1\right)
Variable x cannot be equal to 1 since division by zero is not defined. Multiply both sides of the equation by 2\left(x-1\right).
6x+2=x\times 2\left(x-1\right)
Use the distributive property to multiply 2 by 3x+1.
6x+2=2x^{2}-x\times 2
Use the distributive property to multiply x\times 2 by x-1.
6x+2=2x^{2}-2x
Multiply -1 and 2 to get -2.
6x+2-2x^{2}=-2x
Subtract 2x^{2} from both sides.
6x+2-2x^{2}+2x=0
Add 2x to both sides.
8x+2-2x^{2}=0
Combine 6x and 2x to get 8x.
-2x^{2}+8x+2=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{-8±\sqrt{8^{2}-4\left(-2\right)\times 2}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, 8 for b, and 2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-8±\sqrt{64-4\left(-2\right)\times 2}}{2\left(-2\right)}
Square 8.
x=\frac{-8±\sqrt{64+8\times 2}}{2\left(-2\right)}
Multiply -4 times -2.
x=\frac{-8±\sqrt{64+16}}{2\left(-2\right)}
Multiply 8 times 2.
x=\frac{-8±\sqrt{80}}{2\left(-2\right)}
Add 64 to 16.
x=\frac{-8±4\sqrt{5}}{2\left(-2\right)}
Take the square root of 80.
x=\frac{-8±4\sqrt{5}}{-4}
Multiply 2 times -2.
x=\frac{4\sqrt{5}-8}{-4}
Now solve the equation x=\frac{-8±4\sqrt{5}}{-4} when ± is plus. Add -8 to 4\sqrt{5}.
x=2-\sqrt{5}
Divide -8+4\sqrt{5} by -4.
x=\frac{-4\sqrt{5}-8}{-4}
Now solve the equation x=\frac{-8±4\sqrt{5}}{-4} when ± is minus. Subtract 4\sqrt{5} from -8.
x=\sqrt{5}+2
Divide -8-4\sqrt{5} by -4.
x=2-\sqrt{5} x=\sqrt{5}+2
The equation is now solved.
2\left(3x+1\right)=x\times 2\left(x-1\right)
Variable x cannot be equal to 1 since division by zero is not defined. Multiply both sides of the equation by 2\left(x-1\right).
6x+2=x\times 2\left(x-1\right)
Use the distributive property to multiply 2 by 3x+1.
6x+2=2x^{2}-x\times 2
Use the distributive property to multiply x\times 2 by x-1.
6x+2=2x^{2}-2x
Multiply -1 and 2 to get -2.
6x+2-2x^{2}=-2x
Subtract 2x^{2} from both sides.
6x+2-2x^{2}+2x=0
Add 2x to both sides.
8x+2-2x^{2}=0
Combine 6x and 2x to get 8x.
8x-2x^{2}=-2
Subtract 2 from both sides. Anything subtracted from zero gives its negation.
-2x^{2}+8x=-2
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}+8x}{-2}=-\frac{2}{-2}
Divide both sides by -2.
x^{2}+\frac{8}{-2}x=-\frac{2}{-2}
Dividing by -2 undoes the multiplication by -2.
x^{2}-4x=-\frac{2}{-2}
Divide 8 by -2.
x^{2}-4x=1
Divide -2 by -2.
x^{2}-4x+\left(-2\right)^{2}=1+\left(-2\right)^{2}
Divide -4, the coefficient of the x term, by 2 to get -2. Then add the square of -2 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-4x+4=1+4
Square -2.
x^{2}-4x+4=5
Add 1 to 4.
\left(x-2\right)^{2}=5
Factor x^{2}-4x+4. 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-2\right)^{2}}=\sqrt{5}
Take the square root of both sides of the equation.
x-2=\sqrt{5} x-2=-\sqrt{5}
Simplify.
x=\sqrt{5}+2 x=2-\sqrt{5}
Add 2 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}