Solve for x
x=-1
x=2
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2=x\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 x-1.
2=x^{2}-x
Use the distributive property to multiply x by x-1.
x^{2}-x=2
Swap sides so that all variable terms are on the left hand side.
x^{2}-x-2=0
Subtract 2 from both sides.
x=\frac{-\left(-1\right)±\sqrt{1-4\left(-2\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, -1 for b, and -2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-1\right)±\sqrt{1+8}}{2}
Multiply -4 times -2.
x=\frac{-\left(-1\right)±\sqrt{9}}{2}
Add 1 to 8.
x=\frac{-\left(-1\right)±3}{2}
Take the square root of 9.
x=\frac{1±3}{2}
The opposite of -1 is 1.
x=\frac{4}{2}
Now solve the equation x=\frac{1±3}{2} when ± is plus. Add 1 to 3.
x=2
Divide 4 by 2.
x=-\frac{2}{2}
Now solve the equation x=\frac{1±3}{2} when ± is minus. Subtract 3 from 1.
x=-1
Divide -2 by 2.
x=2 x=-1
The equation is now solved.
2=x\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 x-1.
2=x^{2}-x
Use the distributive property to multiply x by x-1.
x^{2}-x=2
Swap sides so that all variable terms are on the left hand side.
x^{2}-x+\left(-\frac{1}{2}\right)^{2}=2+\left(-\frac{1}{2}\right)^{2}
Divide -1, the coefficient of the x term, by 2 to get -\frac{1}{2}. Then add the square of -\frac{1}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-x+\frac{1}{4}=2+\frac{1}{4}
Square -\frac{1}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}-x+\frac{1}{4}=\frac{9}{4}
Add 2 to \frac{1}{4}.
\left(x-\frac{1}{2}\right)^{2}=\frac{9}{4}
Factor x^{2}-x+\frac{1}{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{1}{2}\right)^{2}}=\sqrt{\frac{9}{4}}
Take the square root of both sides of the equation.
x-\frac{1}{2}=\frac{3}{2} x-\frac{1}{2}=-\frac{3}{2}
Simplify.
x=2 x=-1
Add \frac{1}{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}