Solve for x
x = \frac{12}{5} = 2\frac{2}{5} = 2.4
x=0
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5x^{2}-12x=0
Subtract 12x from both sides.
x\left(5x-12\right)=0
Factor out x.
x=0 x=\frac{12}{5}
To find equation solutions, solve x=0 and 5x-12=0.
5x^{2}-12x=0
Subtract 12x from both sides.
x=\frac{-\left(-12\right)±\sqrt{\left(-12\right)^{2}}}{2\times 5}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 5 for a, -12 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-12\right)±12}{2\times 5}
Take the square root of \left(-12\right)^{2}.
x=\frac{12±12}{2\times 5}
The opposite of -12 is 12.
x=\frac{12±12}{10}
Multiply 2 times 5.
x=\frac{24}{10}
Now solve the equation x=\frac{12±12}{10} when ± is plus. Add 12 to 12.
x=\frac{12}{5}
Reduce the fraction \frac{24}{10} to lowest terms by extracting and canceling out 2.
x=\frac{0}{10}
Now solve the equation x=\frac{12±12}{10} when ± is minus. Subtract 12 from 12.
x=0
Divide 0 by 10.
x=\frac{12}{5} x=0
The equation is now solved.
5x^{2}-12x=0
Subtract 12x from both sides.
\frac{5x^{2}-12x}{5}=\frac{0}{5}
Divide both sides by 5.
x^{2}-\frac{12}{5}x=\frac{0}{5}
Dividing by 5 undoes the multiplication by 5.
x^{2}-\frac{12}{5}x=0
Divide 0 by 5.
x^{2}-\frac{12}{5}x+\left(-\frac{6}{5}\right)^{2}=\left(-\frac{6}{5}\right)^{2}
Divide -\frac{12}{5}, the coefficient of the x term, by 2 to get -\frac{6}{5}. Then add the square of -\frac{6}{5} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{12}{5}x+\frac{36}{25}=\frac{36}{25}
Square -\frac{6}{5} by squaring both the numerator and the denominator of the fraction.
\left(x-\frac{6}{5}\right)^{2}=\frac{36}{25}
Factor x^{2}-\frac{12}{5}x+\frac{36}{25}. 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{6}{5}\right)^{2}}=\sqrt{\frac{36}{25}}
Take the square root of both sides of the equation.
x-\frac{6}{5}=\frac{6}{5} x-\frac{6}{5}=-\frac{6}{5}
Simplify.
x=\frac{12}{5} x=0
Add \frac{6}{5} to both sides of the equation.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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Linear equation
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Matrix
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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
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