Solve for x (complex solution)
x=\frac{3+3\sqrt{7}i}{4}\approx 0.75+1.984313483i
x=\frac{-3\sqrt{7}i+3}{4}\approx 0.75-1.984313483i
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x\left(3x-3\right)=\left(x+3\right)\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+3,x.
3x^{2}-3x=\left(x+3\right)\left(x-3\right)
Use the distributive property to multiply x by 3x-3.
3x^{2}-3x=x^{2}-9
Consider \left(x+3\right)\left(x-3\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}. Square 3.
3x^{2}-3x-x^{2}=-9
Subtract x^{2} from both sides.
2x^{2}-3x=-9
Combine 3x^{2} and -x^{2} to get 2x^{2}.
2x^{2}-3x+9=0
Add 9 to both sides.
x=\frac{-\left(-3\right)±\sqrt{\left(-3\right)^{2}-4\times 2\times 9}}{2\times 2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 2 for a, -3 for b, and 9 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-3\right)±\sqrt{9-4\times 2\times 9}}{2\times 2}
Square -3.
x=\frac{-\left(-3\right)±\sqrt{9-8\times 9}}{2\times 2}
Multiply -4 times 2.
x=\frac{-\left(-3\right)±\sqrt{9-72}}{2\times 2}
Multiply -8 times 9.
x=\frac{-\left(-3\right)±\sqrt{-63}}{2\times 2}
Add 9 to -72.
x=\frac{-\left(-3\right)±3\sqrt{7}i}{2\times 2}
Take the square root of -63.
x=\frac{3±3\sqrt{7}i}{2\times 2}
The opposite of -3 is 3.
x=\frac{3±3\sqrt{7}i}{4}
Multiply 2 times 2.
x=\frac{3+3\sqrt{7}i}{4}
Now solve the equation x=\frac{3±3\sqrt{7}i}{4} when ± is plus. Add 3 to 3i\sqrt{7}.
x=\frac{-3\sqrt{7}i+3}{4}
Now solve the equation x=\frac{3±3\sqrt{7}i}{4} when ± is minus. Subtract 3i\sqrt{7} from 3.
x=\frac{3+3\sqrt{7}i}{4} x=\frac{-3\sqrt{7}i+3}{4}
The equation is now solved.
x\left(3x-3\right)=\left(x+3\right)\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+3,x.
3x^{2}-3x=\left(x+3\right)\left(x-3\right)
Use the distributive property to multiply x by 3x-3.
3x^{2}-3x=x^{2}-9
Consider \left(x+3\right)\left(x-3\right). Multiplication can be transformed into difference of squares using the rule: \left(a-b\right)\left(a+b\right)=a^{2}-b^{2}. Square 3.
3x^{2}-3x-x^{2}=-9
Subtract x^{2} from both sides.
2x^{2}-3x=-9
Combine 3x^{2} and -x^{2} to get 2x^{2}.
\frac{2x^{2}-3x}{2}=-\frac{9}{2}
Divide both sides by 2.
x^{2}-\frac{3}{2}x=-\frac{9}{2}
Dividing by 2 undoes the multiplication by 2.
x^{2}-\frac{3}{2}x+\left(-\frac{3}{4}\right)^{2}=-\frac{9}{2}+\left(-\frac{3}{4}\right)^{2}
Divide -\frac{3}{2}, the coefficient of the x term, by 2 to get -\frac{3}{4}. Then add the square of -\frac{3}{4} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{3}{2}x+\frac{9}{16}=-\frac{9}{2}+\frac{9}{16}
Square -\frac{3}{4} by squaring both the numerator and the denominator of the fraction.
x^{2}-\frac{3}{2}x+\frac{9}{16}=-\frac{63}{16}
Add -\frac{9}{2} to \frac{9}{16} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x-\frac{3}{4}\right)^{2}=-\frac{63}{16}
Factor x^{2}-\frac{3}{2}x+\frac{9}{16}. 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{3}{4}\right)^{2}}=\sqrt{-\frac{63}{16}}
Take the square root of both sides of the equation.
x-\frac{3}{4}=\frac{3\sqrt{7}i}{4} x-\frac{3}{4}=-\frac{3\sqrt{7}i}{4}
Simplify.
x=\frac{3+3\sqrt{7}i}{4} x=\frac{-3\sqrt{7}i+3}{4}
Add \frac{3}{4} to both sides of the equation.
Examples
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{ x } ^ { 2 } - 4 x - 5 = 0
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Linear equation
y = 3x + 4
Arithmetic
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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
\int _ { 0 } ^ { 1 } x e ^ { - x ^ { 2 } } d x
Limits
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