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Solve for x (complex solution)
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\left(x+3\right)\times 2+x\left(-3\right)=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\left(-3\right)=x\left(x+3\right)
Use the distributive property to multiply x+3 by 2.
-x+6=x\left(x+3\right)
Combine 2x and x\left(-3\right) to get -x.
-x+6=x^{2}+3x
Use the distributive property to multiply x by x+3.
-x+6-x^{2}=3x
Subtract x^{2} from both sides.
-x+6-x^{2}-3x=0
Subtract 3x from both sides.
-4x+6-x^{2}=0
Combine -x and -3x to get -4x.
-x^{2}-4x+6=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(-4\right)±\sqrt{\left(-4\right)^{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, -4 for b, and 6 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-4\right)±\sqrt{16-4\left(-1\right)\times 6}}{2\left(-1\right)}
Square -4.
x=\frac{-\left(-4\right)±\sqrt{16+4\times 6}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-\left(-4\right)±\sqrt{16+24}}{2\left(-1\right)}
Multiply 4 times 6.
x=\frac{-\left(-4\right)±\sqrt{40}}{2\left(-1\right)}
Add 16 to 24.
x=\frac{-\left(-4\right)±2\sqrt{10}}{2\left(-1\right)}
Take the square root of 40.
x=\frac{4±2\sqrt{10}}{2\left(-1\right)}
The opposite of -4 is 4.
x=\frac{4±2\sqrt{10}}{-2}
Multiply 2 times -1.
x=\frac{2\sqrt{10}+4}{-2}
Now solve the equation x=\frac{4±2\sqrt{10}}{-2} when ± is plus. Add 4 to 2\sqrt{10}.
x=-\left(\sqrt{10}+2\right)
Divide 4+2\sqrt{10} by -2.
x=\frac{4-2\sqrt{10}}{-2}
Now solve the equation x=\frac{4±2\sqrt{10}}{-2} when ± is minus. Subtract 2\sqrt{10} from 4.
x=\sqrt{10}-2
Divide 4-2\sqrt{10} by -2.
x=-\left(\sqrt{10}+2\right) x=\sqrt{10}-2
The equation is now solved.
\left(x+3\right)\times 2+x\left(-3\right)=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\left(-3\right)=x\left(x+3\right)
Use the distributive property to multiply x+3 by 2.
-x+6=x\left(x+3\right)
Combine 2x and x\left(-3\right) to get -x.
-x+6=x^{2}+3x
Use the distributive property to multiply x by x+3.
-x+6-x^{2}=3x
Subtract x^{2} from both sides.
-x+6-x^{2}-3x=0
Subtract 3x from both sides.
-4x+6-x^{2}=0
Combine -x and -3x to get -4x.
-4x-x^{2}=-6
Subtract 6 from both sides. Anything subtracted from zero gives its negation.
-x^{2}-4x=-6
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{-x^{2}-4x}{-1}=-\frac{6}{-1}
Divide both sides by -1.
x^{2}+\left(-\frac{4}{-1}\right)x=-\frac{6}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}+4x=-\frac{6}{-1}
Divide -4 by -1.
x^{2}+4x=6
Divide -6 by -1.
x^{2}+4x+2^{2}=6+2^{2}
Divide 4, the coefficient of the x term, by 2 to get 2. Then add the square of 2 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+4x+4=6+4
Square 2.
x^{2}+4x+4=10
Add 6 to 4.
\left(x+2\right)^{2}=10
Factor x^{2}+4x+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+2\right)^{2}}=\sqrt{10}
Take the square root of both sides of the equation.
x+2=\sqrt{10} x+2=-\sqrt{10}
Simplify.
x=\sqrt{10}-2 x=-\sqrt{10}-2
Subtract 2 from both sides of the equation.
\left(x+3\right)\times 2+x\left(-3\right)=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\left(-3\right)=x\left(x+3\right)
Use the distributive property to multiply x+3 by 2.
-x+6=x\left(x+3\right)
Combine 2x and x\left(-3\right) to get -x.
-x+6=x^{2}+3x
Use the distributive property to multiply x by x+3.
-x+6-x^{2}=3x
Subtract x^{2} from both sides.
-x+6-x^{2}-3x=0
Subtract 3x from both sides.
-4x+6-x^{2}=0
Combine -x and -3x to get -4x.
-x^{2}-4x+6=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(-4\right)±\sqrt{\left(-4\right)^{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, -4 for b, and 6 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-4\right)±\sqrt{16-4\left(-1\right)\times 6}}{2\left(-1\right)}
Square -4.
x=\frac{-\left(-4\right)±\sqrt{16+4\times 6}}{2\left(-1\right)}
Multiply -4 times -1.
x=\frac{-\left(-4\right)±\sqrt{16+24}}{2\left(-1\right)}
Multiply 4 times 6.
x=\frac{-\left(-4\right)±\sqrt{40}}{2\left(-1\right)}
Add 16 to 24.
x=\frac{-\left(-4\right)±2\sqrt{10}}{2\left(-1\right)}
Take the square root of 40.
x=\frac{4±2\sqrt{10}}{2\left(-1\right)}
The opposite of -4 is 4.
x=\frac{4±2\sqrt{10}}{-2}
Multiply 2 times -1.
x=\frac{2\sqrt{10}+4}{-2}
Now solve the equation x=\frac{4±2\sqrt{10}}{-2} when ± is plus. Add 4 to 2\sqrt{10}.
x=-\left(\sqrt{10}+2\right)
Divide 4+2\sqrt{10} by -2.
x=\frac{4-2\sqrt{10}}{-2}
Now solve the equation x=\frac{4±2\sqrt{10}}{-2} when ± is minus. Subtract 2\sqrt{10} from 4.
x=\sqrt{10}-2
Divide 4-2\sqrt{10} by -2.
x=-\left(\sqrt{10}+2\right) x=\sqrt{10}-2
The equation is now solved.
\left(x+3\right)\times 2+x\left(-3\right)=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\left(-3\right)=x\left(x+3\right)
Use the distributive property to multiply x+3 by 2.
-x+6=x\left(x+3\right)
Combine 2x and x\left(-3\right) to get -x.
-x+6=x^{2}+3x
Use the distributive property to multiply x by x+3.
-x+6-x^{2}=3x
Subtract x^{2} from both sides.
-x+6-x^{2}-3x=0
Subtract 3x from both sides.
-4x+6-x^{2}=0
Combine -x and -3x to get -4x.
-4x-x^{2}=-6
Subtract 6 from both sides. Anything subtracted from zero gives its negation.
-x^{2}-4x=-6
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{-x^{2}-4x}{-1}=-\frac{6}{-1}
Divide both sides by -1.
x^{2}+\left(-\frac{4}{-1}\right)x=-\frac{6}{-1}
Dividing by -1 undoes the multiplication by -1.
x^{2}+4x=-\frac{6}{-1}
Divide -4 by -1.
x^{2}+4x=6
Divide -6 by -1.
x^{2}+4x+2^{2}=6+2^{2}
Divide 4, the coefficient of the x term, by 2 to get 2. Then add the square of 2 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+4x+4=6+4
Square 2.
x^{2}+4x+4=10
Add 6 to 4.
\left(x+2\right)^{2}=10
Factor x^{2}+4x+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+2\right)^{2}}=\sqrt{10}
Take the square root of both sides of the equation.
x+2=\sqrt{10} x+2=-\sqrt{10}
Simplify.
x=\sqrt{10}-2 x=-\sqrt{10}-2
Subtract 2 from both sides of the equation.