Solve for x
x=\sqrt{6}\approx 2.449489743
x=-\sqrt{6}\approx -2.449489743
Graph
Share
Copied to clipboard
\left(x+3\right)\times 2+x=x\left(x+3\right)
Variable x cannot be equal to any of the values -3,0 since division by zero is not defined. Multiply both sides of the equation by x\left(x+3\right), the least common multiple of x,x+3.
2x+6+x=x\left(x+3\right)
Use the distributive property to multiply x+3 by 2.
3x+6=x\left(x+3\right)
Combine 2x and x to get 3x.
3x+6=x^{2}+3x
Use the distributive property to multiply x by x+3.
3x+6-x^{2}=3x
Subtract x^{2} from both sides.
3x+6-x^{2}-3x=0
Subtract 3x from both sides.
6-x^{2}=0
Combine 3x and -3x to get 0.
-x^{2}=-6
Subtract 6 from both sides. Anything subtracted from zero gives its negation.
x^{2}=\frac{-6}{-1}
Divide both sides by -1.
x^{2}=6
Fraction \frac{-6}{-1} can be simplified to 6 by removing the negative sign from both the numerator and the denominator.
x=\sqrt{6} x=-\sqrt{6}
Take the square root of both sides of the equation.
\left(x+3\right)\times 2+x=x\left(x+3\right)
Variable x cannot be equal to any of the values -3,0 since division by zero is not defined. Multiply both sides of the equation by x\left(x+3\right), the least common multiple of x,x+3.
2x+6+x=x\left(x+3\right)
Use the distributive property to multiply x+3 by 2.
3x+6=x\left(x+3\right)
Combine 2x and x to get 3x.
3x+6=x^{2}+3x
Use the distributive property to multiply x by x+3.
3x+6-x^{2}=3x
Subtract x^{2} from both sides.
3x+6-x^{2}-3x=0
Subtract 3x from both sides.
6-x^{2}=0
Combine 3x and -3x to get 0.
-x^{2}+6=0
Quadratic equations like this one, with an x^{2} term but no x term, can still be solved using the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}, once they are put in standard form: ax^{2}+bx+c=0.
x=\frac{0±\sqrt{0^{2}-4\left(-1\right)\times 6}}{2\left(-1\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -1 for a, 0 for b, and 6 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-1\right)\times 6}}{2\left(-1\right)}
Square 0.
x=\frac{0±\sqrt{4\times 6}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{0±\sqrt{24}}{2\left(-1\right)}
Multiply 4 times 6.
x=\frac{0±2\sqrt{6}}{2\left(-1\right)}
Take the square root of 24.
x=\frac{0±2\sqrt{6}}{-2}
Multiply 2 times -1.
x=-\sqrt{6}
Now solve the equation x=\frac{0±2\sqrt{6}}{-2} when ± is plus.
x=\sqrt{6}
Now solve the equation x=\frac{0±2\sqrt{6}}{-2} when ± is minus.
x=-\sqrt{6} x=\sqrt{6}
The equation is now solved.
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}