Solve for x
x = \frac{\sqrt{13} + 5}{6} \approx 1.434258546
x=\frac{5-\sqrt{13}}{6}\approx 0.232408121
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3x^{2}+1-5x=0
Subtract 5x from both sides.
3x^{2}-5x+1=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{-\left(-5\right)±\sqrt{\left(-5\right)^{2}-4\times 3}}{2\times 3}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 3 for a, -5 for b, and 1 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-5\right)±\sqrt{25-4\times 3}}{2\times 3}
Square -5.
x=\frac{-\left(-5\right)±\sqrt{25-12}}{2\times 3}
Multiply -4 times 3.
x=\frac{-\left(-5\right)±\sqrt{13}}{2\times 3}
Add 25 to -12.
x=\frac{5±\sqrt{13}}{2\times 3}
The opposite of -5 is 5.
x=\frac{5±\sqrt{13}}{6}
Multiply 2 times 3.
x=\frac{\sqrt{13}+5}{6}
Now solve the equation x=\frac{5±\sqrt{13}}{6} when ± is plus. Add 5 to \sqrt{13}.
x=\frac{5-\sqrt{13}}{6}
Now solve the equation x=\frac{5±\sqrt{13}}{6} when ± is minus. Subtract \sqrt{13} from 5.
x=\frac{\sqrt{13}+5}{6} x=\frac{5-\sqrt{13}}{6}
The equation is now solved.
3x^{2}+1-5x=0
Subtract 5x from both sides.
3x^{2}-5x=-1
Subtract 1 from both sides. Anything subtracted from zero gives its negation.
\frac{3x^{2}-5x}{3}=-\frac{1}{3}
Divide both sides by 3.
x^{2}-\frac{5}{3}x=-\frac{1}{3}
Dividing by 3 undoes the multiplication by 3.
x^{2}-\frac{5}{3}x+\left(-\frac{5}{6}\right)^{2}=-\frac{1}{3}+\left(-\frac{5}{6}\right)^{2}
Divide -\frac{5}{3}, the coefficient of the x term, by 2 to get -\frac{5}{6}. Then add the square of -\frac{5}{6} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{5}{3}x+\frac{25}{36}=-\frac{1}{3}+\frac{25}{36}
Square -\frac{5}{6} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{5}{3}x+\frac{25}{36}=\frac{13}{36}
Add -\frac{1}{3} to \frac{25}{36} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{5}{6}\right)^{2}=\frac{13}{36}
Factor x^{2}-\frac{5}{3}x+\frac{25}{36}. 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{5}{6}\right)^{2}}=\sqrt{\frac{13}{36}}
Take the square root of both sides of the equation.
x-\frac{5}{6}=\frac{\sqrt{13}}{6} x-\frac{5}{6}=-\frac{\sqrt{13}}{6}
Simplify.
x=\frac{\sqrt{13}+5}{6} x=\frac{5-\sqrt{13}}{6}
Add \frac{5}{6} 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}