Solve for x
x = -\frac{14}{11} = -1\frac{3}{11} \approx -1.272727273
x=1
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\left(3x+6\right)\times 3+\left(3x-6\right)x=\left(x^{2}-4\right)\left(-8\right)
Variable x cannot be equal to any of the values -2,2 since division by zero is not defined. Multiply both sides of the equation by 3\left(x-2\right)\left(x+2\right), the least common multiple of x-2,x+2,3.
9x+18+\left(3x-6\right)x=\left(x^{2}-4\right)\left(-8\right)
Use the distributive property to multiply 3x+6 by 3.
9x+18+3x^{2}-6x=\left(x^{2}-4\right)\left(-8\right)
Use the distributive property to multiply 3x-6 by x.
3x+18+3x^{2}=\left(x^{2}-4\right)\left(-8\right)
Combine 9x and -6x to get 3x.
3x+18+3x^{2}=-8x^{2}+32
Use the distributive property to multiply x^{2}-4 by -8.
3x+18+3x^{2}+8x^{2}=32
Add 8x^{2} to both sides.
3x+18+11x^{2}=32
Combine 3x^{2} and 8x^{2} to get 11x^{2}.
3x+18+11x^{2}-32=0
Subtract 32 from both sides.
3x-14+11x^{2}=0
Subtract 32 from 18 to get -14.
11x^{2}+3x-14=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{-3±\sqrt{3^{2}-4\times 11\left(-14\right)}}{2\times 11}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 11 for a, 3 for b, and -14 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-3±\sqrt{9-4\times 11\left(-14\right)}}{2\times 11}
Square 3.
x=\frac{-3±\sqrt{9-44\left(-14\right)}}{2\times 11}
Multiply -4 times 11.
x=\frac{-3±\sqrt{9+616}}{2\times 11}
Multiply -44 times -14.
x=\frac{-3±\sqrt{625}}{2\times 11}
Add 9 to 616.
x=\frac{-3±25}{2\times 11}
Take the square root of 625.
x=\frac{-3±25}{22}
Multiply 2 times 11.
x=\frac{22}{22}
Now solve the equation x=\frac{-3±25}{22} when ± is plus. Add -3 to 25.
x=1
Divide 22 by 22.
x=-\frac{28}{22}
Now solve the equation x=\frac{-3±25}{22} when ± is minus. Subtract 25 from -3.
x=-\frac{14}{11}
Reduce the fraction \frac{-28}{22} to lowest terms by extracting and canceling out 2.
x=1 x=-\frac{14}{11}
The equation is now solved.
\left(3x+6\right)\times 3+\left(3x-6\right)x=\left(x^{2}-4\right)\left(-8\right)
Variable x cannot be equal to any of the values -2,2 since division by zero is not defined. Multiply both sides of the equation by 3\left(x-2\right)\left(x+2\right), the least common multiple of x-2,x+2,3.
9x+18+\left(3x-6\right)x=\left(x^{2}-4\right)\left(-8\right)
Use the distributive property to multiply 3x+6 by 3.
9x+18+3x^{2}-6x=\left(x^{2}-4\right)\left(-8\right)
Use the distributive property to multiply 3x-6 by x.
3x+18+3x^{2}=\left(x^{2}-4\right)\left(-8\right)
Combine 9x and -6x to get 3x.
3x+18+3x^{2}=-8x^{2}+32
Use the distributive property to multiply x^{2}-4 by -8.
3x+18+3x^{2}+8x^{2}=32
Add 8x^{2} to both sides.
3x+18+11x^{2}=32
Combine 3x^{2} and 8x^{2} to get 11x^{2}.
3x+11x^{2}=32-18
Subtract 18 from both sides.
3x+11x^{2}=14
Subtract 18 from 32 to get 14.
11x^{2}+3x=14
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{11x^{2}+3x}{11}=\frac{14}{11}
Divide both sides by 11.
x^{2}+\frac{3}{11}x=\frac{14}{11}
Dividing by 11 undoes the multiplication by 11.
x^{2}+\frac{3}{11}x+\left(\frac{3}{22}\right)^{2}=\frac{14}{11}+\left(\frac{3}{22}\right)^{2}
Divide \frac{3}{11}, the coefficient of the x term, by 2 to get \frac{3}{22}. Then add the square of \frac{3}{22} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+\frac{3}{11}x+\frac{9}{484}=\frac{14}{11}+\frac{9}{484}
Square \frac{3}{22} by squaring both the numerator and the denominator of the fraction.
x^{2}+\frac{3}{11}x+\frac{9}{484}=\frac{625}{484}
Add \frac{14}{11} to \frac{9}{484} by finding a common denominator and adding the numerators. Then reduce the fraction to lowest terms if possible.
\left(x+\frac{3}{22}\right)^{2}=\frac{625}{484}
Factor x^{2}+\frac{3}{11}x+\frac{9}{484}. 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}{22}\right)^{2}}=\sqrt{\frac{625}{484}}
Take the square root of both sides of the equation.
x+\frac{3}{22}=\frac{25}{22} x+\frac{3}{22}=-\frac{25}{22}
Simplify.
x=1 x=-\frac{14}{11}
Subtract \frac{3}{22} from both sides of the equation.
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Simultaneous equation
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Differentiation
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Integration
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Limits
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