Solve for x
x=\frac{1}{2}=0.5
x=\frac{2}{3}\approx 0.666666667
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6x^{2}+2-7x=0
Subtract 7x from both sides.
6x^{2}-7x+2=0
Rearrange the polynomial to put it in standard form. Place the terms in order from highest to lowest power.
a+b=-7 ab=6\times 2=12
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as 6x^{2}+ax+bx+2. To find a and b, set up a system to be solved.
-1,-12 -2,-6 -3,-4
Since ab is positive, a and b have the same sign. Since a+b is negative, a and b are both negative. List all such integer pairs that give product 12.
-1-12=-13 -2-6=-8 -3-4=-7
Calculate the sum for each pair.
a=-4 b=-3
The solution is the pair that gives sum -7.
\left(6x^{2}-4x\right)+\left(-3x+2\right)
Rewrite 6x^{2}-7x+2 as \left(6x^{2}-4x\right)+\left(-3x+2\right).
2x\left(3x-2\right)-\left(3x-2\right)
Factor out 2x in the first and -1 in the second group.
\left(3x-2\right)\left(2x-1\right)
Factor out common term 3x-2 by using distributive property.
x=\frac{2}{3} x=\frac{1}{2}
To find equation solutions, solve 3x-2=0 and 2x-1=0.
6x^{2}+2-7x=0
Subtract 7x from both sides.
6x^{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{-\left(-7\right)±\sqrt{\left(-7\right)^{2}-4\times 6\times 2}}{2\times 6}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 6 for a, -7 for b, and 2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-7\right)±\sqrt{49-4\times 6\times 2}}{2\times 6}
Square -7.
x=\frac{-\left(-7\right)±\sqrt{49-24\times 2}}{2\times 6}
Multiply -4 times 6.
x=\frac{-\left(-7\right)±\sqrt{49-48}}{2\times 6}
Multiply -24 times 2.
x=\frac{-\left(-7\right)±\sqrt{1}}{2\times 6}
Add 49 to -48.
x=\frac{-\left(-7\right)±1}{2\times 6}
Take the square root of 1.
x=\frac{7±1}{2\times 6}
The opposite of -7 is 7.
x=\frac{7±1}{12}
Multiply 2 times 6.
x=\frac{8}{12}
Now solve the equation x=\frac{7±1}{12} when ± is plus. Add 7 to 1.
x=\frac{2}{3}
Reduce the fraction \frac{8}{12} to lowest terms by extracting and canceling out 4.
x=\frac{6}{12}
Now solve the equation x=\frac{7±1}{12} when ± is minus. Subtract 1 from 7.
x=\frac{1}{2}
Reduce the fraction \frac{6}{12} to lowest terms by extracting and canceling out 6.
x=\frac{2}{3} x=\frac{1}{2}
The equation is now solved.
6x^{2}+2-7x=0
Subtract 7x from both sides.
6x^{2}-7x=-2
Subtract 2 from both sides. Anything subtracted from zero gives its negation.
\frac{6x^{2}-7x}{6}=-\frac{2}{6}
Divide both sides by 6.
x^{2}-\frac{7}{6}x=-\frac{2}{6}
Dividing by 6 undoes the multiplication by 6.
x^{2}-\frac{7}{6}x=-\frac{1}{3}
Reduce the fraction \frac{-2}{6} to lowest terms by extracting and canceling out 2.
x^{2}-\frac{7}{6}x+\left(-\frac{7}{12}\right)^{2}=-\frac{1}{3}+\left(-\frac{7}{12}\right)^{2}
Divide -\frac{7}{6}, the coefficient of the x term, by 2 to get -\frac{7}{12}. Then add the square of -\frac{7}{12} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{7}{6}x+\frac{49}{144}=-\frac{1}{3}+\frac{49}{144}
Square -\frac{7}{12} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{7}{6}x+\frac{49}{144}=\frac{1}{144}
Add -\frac{1}{3} to \frac{49}{144} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{7}{12}\right)^{2}=\frac{1}{144}
Factor x^{2}-\frac{7}{6}x+\frac{49}{144}. 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}{12}\right)^{2}}=\sqrt{\frac{1}{144}}
Take the square root of both sides of the equation.
x-\frac{7}{12}=\frac{1}{12} x-\frac{7}{12}=-\frac{1}{12}
Simplify.
x=\frac{2}{3} x=\frac{1}{2}
Add \frac{7}{12} 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}