Solve for x
x=1
x = \frac{13}{12} = 1\frac{1}{12} \approx 1.083333333
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12x^{2}-25x+13=0
Divide both sides by 2.
a+b=-25 ab=12\times 13=156
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as 12x^{2}+ax+bx+13. To find a and b, set up a system to be solved.
-1,-156 -2,-78 -3,-52 -4,-39 -6,-26 -12,-13
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 156.
-1-156=-157 -2-78=-80 -3-52=-55 -4-39=-43 -6-26=-32 -12-13=-25
Calculate the sum for each pair.
a=-13 b=-12
The solution is the pair that gives sum -25.
\left(12x^{2}-13x\right)+\left(-12x+13\right)
Rewrite 12x^{2}-25x+13 as \left(12x^{2}-13x\right)+\left(-12x+13\right).
x\left(12x-13\right)-\left(12x-13\right)
Factor out x in the first and -1 in the second group.
\left(12x-13\right)\left(x-1\right)
Factor out common term 12x-13 by using distributive property.
x=\frac{13}{12} x=1
To find equation solutions, solve 12x-13=0 and x-1=0.
24x^{2}-50x+26=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(-50\right)±\sqrt{\left(-50\right)^{2}-4\times 24\times 26}}{2\times 24}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 24 for a, -50 for b, and 26 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-50\right)±\sqrt{2500-4\times 24\times 26}}{2\times 24}
Square -50.
x=\frac{-\left(-50\right)±\sqrt{2500-96\times 26}}{2\times 24}
Multiply -4 times 24.
x=\frac{-\left(-50\right)±\sqrt{2500-2496}}{2\times 24}
Multiply -96 times 26.
x=\frac{-\left(-50\right)±\sqrt{4}}{2\times 24}
Add 2500 to -2496.
x=\frac{-\left(-50\right)±2}{2\times 24}
Take the square root of 4.
x=\frac{50±2}{2\times 24}
The opposite of -50 is 50.
x=\frac{50±2}{48}
Multiply 2 times 24.
x=\frac{52}{48}
Now solve the equation x=\frac{50±2}{48} when ± is plus. Add 50 to 2.
x=\frac{13}{12}
Reduce the fraction \frac{52}{48} to lowest terms by extracting and canceling out 4.
x=\frac{48}{48}
Now solve the equation x=\frac{50±2}{48} when ± is minus. Subtract 2 from 50.
x=1
Divide 48 by 48.
x=\frac{13}{12} x=1
The equation is now solved.
24x^{2}-50x+26=0
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
24x^{2}-50x+26-26=-26
Subtract 26 from both sides of the equation.
24x^{2}-50x=-26
Subtracting 26 from itself leaves 0.
\frac{24x^{2}-50x}{24}=-\frac{26}{24}
Divide both sides by 24.
x^{2}+\left(-\frac{50}{24}\right)x=-\frac{26}{24}
Dividing by 24 undoes the multiplication by 24.
x^{2}-\frac{25}{12}x=-\frac{26}{24}
Reduce the fraction \frac{-50}{24} to lowest terms by extracting and canceling out 2.
x^{2}-\frac{25}{12}x=-\frac{13}{12}
Reduce the fraction \frac{-26}{24} to lowest terms by extracting and canceling out 2.
x^{2}-\frac{25}{12}x+\left(-\frac{25}{24}\right)^{2}=-\frac{13}{12}+\left(-\frac{25}{24}\right)^{2}
Divide -\frac{25}{12}, the coefficient of the x term, by 2 to get -\frac{25}{24}. Then add the square of -\frac{25}{24} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{25}{12}x+\frac{625}{576}=-\frac{13}{12}+\frac{625}{576}
Square -\frac{25}{24} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{25}{12}x+\frac{625}{576}=\frac{1}{576}
Add -\frac{13}{12} to \frac{625}{576} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{25}{24}\right)^{2}=\frac{1}{576}
Factor x^{2}-\frac{25}{12}x+\frac{625}{576}. 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{25}{24}\right)^{2}}=\sqrt{\frac{1}{576}}
Take the square root of both sides of the equation.
x-\frac{25}{24}=\frac{1}{24} x-\frac{25}{24}=-\frac{1}{24}
Simplify.
x=\frac{13}{12} x=1
Add \frac{25}{24} to both sides of the equation.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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4 \sin \theta \cos \theta = 2 \sin \theta
Linear equation
y = 3x + 4
Arithmetic
699 * 533
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
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Limits
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