Solve for x
x=-1
x=6
Graph
Share
Copied to clipboard
\left(x-2\right)x=\left(x+2\right)\times 3
Variable x cannot be equal to any of the values -2,2,3 since division by zero is not defined. Multiply both sides of the equation by \left(x-3\right)\left(x-2\right)\left(x+2\right), the least common multiple of x^{2}-x-6,x^{2}-5x+6.
x^{2}-2x=\left(x+2\right)\times 3
Use the distributive property to multiply x-2 by x.
x^{2}-2x=3x+6
Use the distributive property to multiply x+2 by 3.
x^{2}-2x-3x=6
Subtract 3x from both sides.
x^{2}-5x=6
Combine -2x and -3x to get -5x.
x^{2}-5x-6=0
Subtract 6 from both sides.
a+b=-5 ab=-6
To solve the equation, factor x^{2}-5x-6 using formula x^{2}+\left(a+b\right)x+ab=\left(x+a\right)\left(x+b\right). To find a and b, set up a system to be solved.
1,-6 2,-3
Since ab is negative, a and b have the opposite signs. Since a+b is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product -6.
1-6=-5 2-3=-1
Calculate the sum for each pair.
a=-6 b=1
The solution is the pair that gives sum -5.
\left(x-6\right)\left(x+1\right)
Rewrite factored expression \left(x+a\right)\left(x+b\right) using the obtained values.
x=6 x=-1
To find equation solutions, solve x-6=0 and x+1=0.
\left(x-2\right)x=\left(x+2\right)\times 3
Variable x cannot be equal to any of the values -2,2,3 since division by zero is not defined. Multiply both sides of the equation by \left(x-3\right)\left(x-2\right)\left(x+2\right), the least common multiple of x^{2}-x-6,x^{2}-5x+6.
x^{2}-2x=\left(x+2\right)\times 3
Use the distributive property to multiply x-2 by x.
x^{2}-2x=3x+6
Use the distributive property to multiply x+2 by 3.
x^{2}-2x-3x=6
Subtract 3x from both sides.
x^{2}-5x=6
Combine -2x and -3x to get -5x.
x^{2}-5x-6=0
Subtract 6 from both sides.
a+b=-5 ab=1\left(-6\right)=-6
To solve the equation, factor the left hand side by grouping. First, left hand side needs to be rewritten as x^{2}+ax+bx-6. To find a and b, set up a system to be solved.
1,-6 2,-3
Since ab is negative, a and b have the opposite signs. Since a+b is negative, the negative number has greater absolute value than the positive. List all such integer pairs that give product -6.
1-6=-5 2-3=-1
Calculate the sum for each pair.
a=-6 b=1
The solution is the pair that gives sum -5.
\left(x^{2}-6x\right)+\left(x-6\right)
Rewrite x^{2}-5x-6 as \left(x^{2}-6x\right)+\left(x-6\right).
x\left(x-6\right)+x-6
Factor out x in x^{2}-6x.
\left(x-6\right)\left(x+1\right)
Factor out common term x-6 by using distributive property.
x=6 x=-1
To find equation solutions, solve x-6=0 and x+1=0.
\left(x-2\right)x=\left(x+2\right)\times 3
Variable x cannot be equal to any of the values -2,2,3 since division by zero is not defined. Multiply both sides of the equation by \left(x-3\right)\left(x-2\right)\left(x+2\right), the least common multiple of x^{2}-x-6,x^{2}-5x+6.
x^{2}-2x=\left(x+2\right)\times 3
Use the distributive property to multiply x-2 by x.
x^{2}-2x=3x+6
Use the distributive property to multiply x+2 by 3.
x^{2}-2x-3x=6
Subtract 3x from both sides.
x^{2}-5x=6
Combine -2x and -3x to get -5x.
x^{2}-5x-6=0
Subtract 6 from both sides.
x=\frac{-\left(-5\right)±\sqrt{\left(-5\right)^{2}-4\left(-6\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, -5 for b, and -6 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-5\right)±\sqrt{25-4\left(-6\right)}}{2}
Square -5.
x=\frac{-\left(-5\right)±\sqrt{25+24}}{2}
Multiply -4 times -6.
x=\frac{-\left(-5\right)±\sqrt{49}}{2}
Add 25 to 24.
x=\frac{-\left(-5\right)±7}{2}
Take the square root of 49.
x=\frac{5±7}{2}
The opposite of -5 is 5.
x=\frac{12}{2}
Now solve the equation x=\frac{5±7}{2} when ± is plus. Add 5 to 7.
x=6
Divide 12 by 2.
x=-\frac{2}{2}
Now solve the equation x=\frac{5±7}{2} when ± is minus. Subtract 7 from 5.
x=-1
Divide -2 by 2.
x=6 x=-1
The equation is now solved.
\left(x-2\right)x=\left(x+2\right)\times 3
Variable x cannot be equal to any of the values -2,2,3 since division by zero is not defined. Multiply both sides of the equation by \left(x-3\right)\left(x-2\right)\left(x+2\right), the least common multiple of x^{2}-x-6,x^{2}-5x+6.
x^{2}-2x=\left(x+2\right)\times 3
Use the distributive property to multiply x-2 by x.
x^{2}-2x=3x+6
Use the distributive property to multiply x+2 by 3.
x^{2}-2x-3x=6
Subtract 3x from both sides.
x^{2}-5x=6
Combine -2x and -3x to get -5x.
x^{2}-5x+\left(-\frac{5}{2}\right)^{2}=6+\left(-\frac{5}{2}\right)^{2}
Divide -5, the coefficient of the x term, by 2 to get -\frac{5}{2}. Then add the square of -\frac{5}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-5x+\frac{25}{4}=6+\frac{25}{4}
Square -\frac{5}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}-5x+\frac{25}{4}=\frac{49}{4}
Add 6 to \frac{25}{4}.
\left(x-\frac{5}{2}\right)^{2}=\frac{49}{4}
Factor x^{2}-5x+\frac{25}{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{5}{2}\right)^{2}}=\sqrt{\frac{49}{4}}
Take the square root of both sides of the equation.
x-\frac{5}{2}=\frac{7}{2} x-\frac{5}{2}=-\frac{7}{2}
Simplify.
x=6 x=-1
Add \frac{5}{2} 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}