Solve for x
x = \frac{3}{2} = 1\frac{1}{2} = 1.5
x = \frac{4}{3} = 1\frac{1}{3} \approx 1.333333333
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6x^{2}-17x=-12
Subtract 17x from both sides.
6x^{2}-17x+12=0
Add 12 to both sides.
a+b=-17 ab=6\times 12=72
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as 6x^{2}+ax+bx+12. To find a and b, set up a system to be solved.
-1,-72 -2,-36 -3,-24 -4,-18 -6,-12 -8,-9
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 72.
-1-72=-73 -2-36=-38 -3-24=-27 -4-18=-22 -6-12=-18 -8-9=-17
Calculate the sum for each pair.
a=-9 b=-8
The solution is the pair that gives sum -17.
\left(6x^{2}-9x\right)+\left(-8x+12\right)
Rewrite 6x^{2}-17x+12 as \left(6x^{2}-9x\right)+\left(-8x+12\right).
3x\left(2x-3\right)-4\left(2x-3\right)
Factor out 3x in the first and -4 in the second group.
\left(2x-3\right)\left(3x-4\right)
Factor out common term 2x-3 by using distributive property.
x=\frac{3}{2} x=\frac{4}{3}
To find equation solutions, solve 2x-3=0 and 3x-4=0.
6x^{2}-17x=-12
Subtract 17x from both sides.
6x^{2}-17x+12=0
Add 12 to both sides.
x=\frac{-\left(-17\right)±\sqrt{\left(-17\right)^{2}-4\times 6\times 12}}{2\times 6}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 6 for a, -17 for b, and 12 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-17\right)±\sqrt{289-4\times 6\times 12}}{2\times 6}
Square -17.
x=\frac{-\left(-17\right)±\sqrt{289-24\times 12}}{2\times 6}
Multiply -4 times 6.
x=\frac{-\left(-17\right)±\sqrt{289-288}}{2\times 6}
Multiply -24 times 12.
x=\frac{-\left(-17\right)±\sqrt{1}}{2\times 6}
Add 289 to -288.
x=\frac{-\left(-17\right)±1}{2\times 6}
Take the square root of 1.
x=\frac{17±1}{2\times 6}
The opposite of -17 is 17.
x=\frac{17±1}{12}
Multiply 2 times 6.
x=\frac{18}{12}
Now solve the equation x=\frac{17±1}{12} when ± is plus. Add 17 to 1.
x=\frac{3}{2}
Reduce the fraction \frac{18}{12} to lowest terms by extracting and canceling out 6.
x=\frac{16}{12}
Now solve the equation x=\frac{17±1}{12} when ± is minus. Subtract 1 from 17.
x=\frac{4}{3}
Reduce the fraction \frac{16}{12} to lowest terms by extracting and canceling out 4.
x=\frac{3}{2} x=\frac{4}{3}
The equation is now solved.
6x^{2}-17x=-12
Subtract 17x from both sides.
\frac{6x^{2}-17x}{6}=-\frac{12}{6}
Divide both sides by 6.
x^{2}-\frac{17}{6}x=-\frac{12}{6}
Dividing by 6 undoes the multiplication by 6.
x^{2}-\frac{17}{6}x=-2
Divide -12 by 6.
x^{2}-\frac{17}{6}x+\left(-\frac{17}{12}\right)^{2}=-2+\left(-\frac{17}{12}\right)^{2}
Divide -\frac{17}{6}, the coefficient of the x term, by 2 to get -\frac{17}{12}. Then add the square of -\frac{17}{12} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{17}{6}x+\frac{289}{144}=-2+\frac{289}{144}
Square -\frac{17}{12} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{17}{6}x+\frac{289}{144}=\frac{1}{144}
Add -2 to \frac{289}{144}.
\left(x-\frac{17}{12}\right)^{2}=\frac{1}{144}
Factor x^{2}-\frac{17}{6}x+\frac{289}{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{17}{12}\right)^{2}}=\sqrt{\frac{1}{144}}
Take the square root of both sides of the equation.
x-\frac{17}{12}=\frac{1}{12} x-\frac{17}{12}=-\frac{1}{12}
Simplify.
x=\frac{3}{2} x=\frac{4}{3}
Add \frac{17}{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}