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2\left(1+3x\right)=\left(x-1\right)x
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), the least common multiple of x-1,2.
2+6x=\left(x-1\right)x
Use the distributive property to multiply 2 by 1+3x.
2+6x=x^{2}-x
Use the distributive property to multiply x-1 by x.
2+6x-x^{2}=-x
Subtract x^{2} from both sides.
2+6x-x^{2}+x=0
Add x to both sides.
2+7x-x^{2}=0
Combine 6x and x to get 7x.
-x^{2}+7x+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{-7±\sqrt{7^{2}-4\left(-1\right)\times 2}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 7 for b, and 2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-7±\sqrt{49-4\left(-1\right)\times 2}}{2\left(-1\right)}
Square 7.
x=\frac{-7±\sqrt{49+4\times 2}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-7±\sqrt{49+8}}{2\left(-1\right)}
Multiply 4 times 2.
x=\frac{-7±\sqrt{57}}{2\left(-1\right)}
Add 49 to 8.
x=\frac{-7±\sqrt{57}}{-2}
Multiply 2 times -1.
x=\frac{\sqrt{57}-7}{-2}
Now solve the equation x=\frac{-7±\sqrt{57}}{-2} when ± is plus. Add -7 to \sqrt{57}.
x=\frac{7-\sqrt{57}}{2}
Divide -7+\sqrt{57} by -2.
x=\frac{-\sqrt{57}-7}{-2}
Now solve the equation x=\frac{-7±\sqrt{57}}{-2} when ± is minus. Subtract \sqrt{57} from -7.
x=\frac{\sqrt{57}+7}{2}
Divide -7-\sqrt{57} by -2.
x=\frac{7-\sqrt{57}}{2} x=\frac{\sqrt{57}+7}{2}
The equation is now solved.
2\left(1+3x\right)=\left(x-1\right)x
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), the least common multiple of x-1,2.
2+6x=\left(x-1\right)x
Use the distributive property to multiply 2 by 1+3x.
2+6x=x^{2}-x
Use the distributive property to multiply x-1 by x.
2+6x-x^{2}=-x
Subtract x^{2} from both sides.
2+6x-x^{2}+x=0
Add x to both sides.
2+7x-x^{2}=0
Combine 6x and x to get 7x.
7x-x^{2}=-2
Subtract 2 from both sides. Anything subtracted from zero gives its negation.
-x^{2}+7x=-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{-x^{2}+7x}{-1}=-\frac{2}{-1}
Divide both sides by -1.
x^{2}+\frac{7}{-1}x=-\frac{2}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}-7x=-\frac{2}{-1}
Divide 7 by -1.
x^{2}-7x=2
Divide -2 by -1.
x^{2}-7x+\left(-\frac{7}{2}\right)^{2}=2+\left(-\frac{7}{2}\right)^{2}
Divide -7, the coefficient of the x term, by 2 to get -\frac{7}{2}. Then add the square of -\frac{7}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-7x+\frac{49}{4}=2+\frac{49}{4}
Square -\frac{7}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}-7x+\frac{49}{4}=\frac{57}{4}
Add 2 to \frac{49}{4}.
\left(x-\frac{7}{2}\right)^{2}=\frac{57}{4}
Factor x^{2}-7x+\frac{49}{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-\frac{7}{2}\right)^{2}}=\sqrt{\frac{57}{4}}
Take the square root of both sides of the equation.
x-\frac{7}{2}=\frac{\sqrt{57}}{2} x-\frac{7}{2}=-\frac{\sqrt{57}}{2}
Simplify.
x=\frac{\sqrt{57}+7}{2} x=\frac{7-\sqrt{57}}{2}
Add \frac{7}{2} to both sides of the equation.