Solve for x
x=3
x=0
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2x^{2}-6x=0
Use the distributive property to multiply 2x by x-3.
x\left(2x-6\right)=0
Factor out x.
x=0 x=3
To find equation solutions, solve x=0 and 2x-6=0.
2x^{2}-6x=0
Use the distributive property to multiply 2x by x-3.
x=\frac{-\left(-6\right)±\sqrt{\left(-6\right)^{2}}}{2\times 2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 2 for a, -6 for b, and 0 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-6\right)±6}{2\times 2}
Take the square root of \left(-6\right)^{2}.
x=\frac{6±6}{2\times 2}
The opposite of -6 is 6.
x=\frac{6±6}{4}
Multiply 2 times 2.
x=\frac{12}{4}
Now solve the equation x=\frac{6±6}{4} when ± is plus. Add 6 to 6.
x=3
Divide 12 by 4.
x=\frac{0}{4}
Now solve the equation x=\frac{6±6}{4} when ± is minus. Subtract 6 from 6.
x=0
Divide 0 by 4.
x=3 x=0
The equation is now solved.
2x^{2}-6x=0
Use the distributive property to multiply 2x by x-3.
\frac{2x^{2}-6x}{2}=\frac{0}{2}
Divide both sides by 2.
x^{2}+\left(-\frac{6}{2}\right)x=\frac{0}{2}
Dividing by 2 undoes the multiplication by 2.
x^{2}-3x=\frac{0}{2}
Divide -6 by 2.
x^{2}-3x=0
Divide 0 by 2.
x^{2}-3x+\left(-\frac{3}{2}\right)^{2}=\left(-\frac{3}{2}\right)^{2}
Divide -3, the coefficient of the x term, by 2 to get -\frac{3}{2}. Then add the square of -\frac{3}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-3x+\frac{9}{4}=\frac{9}{4}
Square -\frac{3}{2} by squaring both the numerator and the denominator of the fraction.
\left(x-\frac{3}{2}\right)^{2}=\frac{9}{4}
Factor x^{2}-3x+\frac{9}{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{3}{2}\right)^{2}}=\sqrt{\frac{9}{4}}
Take the square root of both sides of the equation.
x-\frac{3}{2}=\frac{3}{2} x-\frac{3}{2}=-\frac{3}{2}
Simplify.
x=3 x=0
Add \frac{3}{2} to both sides of the equation.
Examples
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Linear equation
y = 3x + 4
Arithmetic
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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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