Solve for x
x = \frac{\sqrt{13} + 7}{6} \approx 1.767591879
x=\frac{7-\sqrt{13}}{6}\approx 0.565741454
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x+x^{2}-3x+3=x\left(4-2x\right)+x
Use the distributive property to multiply x by x-3.
-2x+x^{2}+3=x\left(4-2x\right)+x
Combine x and -3x to get -2x.
-2x+x^{2}+3=4x-2x^{2}+x
Use the distributive property to multiply x by 4-2x.
-2x+x^{2}+3=5x-2x^{2}
Combine 4x and x to get 5x.
-2x+x^{2}+3-5x=-2x^{2}
Subtract 5x from both sides.
-7x+x^{2}+3=-2x^{2}
Combine -2x and -5x to get -7x.
-7x+x^{2}+3+2x^{2}=0
Add 2x^{2} to both sides.
-7x+3x^{2}+3=0
Combine x^{2} and 2x^{2} to get 3x^{2}.
3x^{2}-7x+3=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 3\times 3}}{2\times 3}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 3 for a, -7 for b, and 3 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-7\right)±\sqrt{49-4\times 3\times 3}}{2\times 3}
Square -7.
x=\frac{-\left(-7\right)±\sqrt{49-12\times 3}}{2\times 3}
Multiply -4 times 3.
x=\frac{-\left(-7\right)±\sqrt{49-36}}{2\times 3}
Multiply -12 times 3.
x=\frac{-\left(-7\right)±\sqrt{13}}{2\times 3}
Add 49 to -36.
x=\frac{7±\sqrt{13}}{2\times 3}
The opposite of -7 is 7.
x=\frac{7±\sqrt{13}}{6}
Multiply 2 times 3.
x=\frac{\sqrt{13}+7}{6}
Now solve the equation x=\frac{7±\sqrt{13}}{6} when ± is plus. Add 7 to \sqrt{13}.
x=\frac{7-\sqrt{13}}{6}
Now solve the equation x=\frac{7±\sqrt{13}}{6} when ± is minus. Subtract \sqrt{13} from 7.
x=\frac{\sqrt{13}+7}{6} x=\frac{7-\sqrt{13}}{6}
The equation is now solved.
x+x^{2}-3x+3=x\left(4-2x\right)+x
Use the distributive property to multiply x by x-3.
-2x+x^{2}+3=x\left(4-2x\right)+x
Combine x and -3x to get -2x.
-2x+x^{2}+3=4x-2x^{2}+x
Use the distributive property to multiply x by 4-2x.
-2x+x^{2}+3=5x-2x^{2}
Combine 4x and x to get 5x.
-2x+x^{2}+3-5x=-2x^{2}
Subtract 5x from both sides.
-7x+x^{2}+3=-2x^{2}
Combine -2x and -5x to get -7x.
-7x+x^{2}+3+2x^{2}=0
Add 2x^{2} to both sides.
-7x+3x^{2}+3=0
Combine x^{2} and 2x^{2} to get 3x^{2}.
-7x+3x^{2}=-3
Subtract 3 from both sides. Anything subtracted from zero gives its negation.
3x^{2}-7x=-3
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.
\frac{3x^{2}-7x}{3}=-\frac{3}{3}
Divide both sides by 3.
x^{2}-\frac{7}{3}x=-\frac{3}{3}
Dividing by 3 undoes the multiplication by 3.
x^{2}-\frac{7}{3}x=-1
Divide -3 by 3.
x^{2}-\frac{7}{3}x+\left(-\frac{7}{6}\right)^{2}=-1+\left(-\frac{7}{6}\right)^{2}
Divide -\frac{7}{3}, the coefficient of the x term, by 2 to get -\frac{7}{6}. Then add the square of -\frac{7}{6} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{7}{3}x+\frac{49}{36}=-1+\frac{49}{36}
Square -\frac{7}{6} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{7}{3}x+\frac{49}{36}=\frac{13}{36}
Add -1 to \frac{49}{36}.
\left(x-\frac{7}{6}\right)^{2}=\frac{13}{36}
Factor x^{2}-\frac{7}{3}x+\frac{49}{36}. 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}{6}\right)^{2}}=\sqrt{\frac{13}{36}}
Take the square root of both sides of the equation.
x-\frac{7}{6}=\frac{\sqrt{13}}{6} x-\frac{7}{6}=-\frac{\sqrt{13}}{6}
Simplify.
x=\frac{\sqrt{13}+7}{6} x=\frac{7-\sqrt{13}}{6}
Add \frac{7}{6} to both sides of the equation.
Examples
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{ 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}