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\left(3x+9\right)\left(2x-3\right)-\left(4x+12\right)x=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
Variable x cannot be equal to -3 since division by zero is not defined. Multiply both sides of the equation by 12\left(x+3\right), the least common multiple of 4,3,x+3,12.
6x^{2}+9x-27-\left(4x+12\right)x=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
Use the distributive property to multiply 3x+9 by 2x-3 and combine like terms.
6x^{2}+9x-27-\left(4x^{2}+12x\right)=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
Use the distributive property to multiply 4x+12 by x.
6x^{2}+9x-27-4x^{2}-12x=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
To find the opposite of 4x^{2}+12x, find the opposite of each term.
2x^{2}+9x-27-12x=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
Combine 6x^{2} and -4x^{2} to get 2x^{2}.
2x^{2}-3x-27=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
Combine 9x and -12x to get -3x.
2x^{2}-3x-27=12-25\left(x+3\right)
Multiply 12 and -\frac{25}{12} to get -25.
2x^{2}-3x-27=12-25x-75
Use the distributive property to multiply -25 by x+3.
2x^{2}-3x-27=-63-25x
Subtract 75 from 12 to get -63.
2x^{2}-3x-27-\left(-63\right)=-25x
Subtract -63 from both sides.
2x^{2}-3x-27+63=-25x
The opposite of -63 is 63.
2x^{2}-3x-27+63+25x=0
Add 25x to both sides.
2x^{2}-3x+36+25x=0
Add -27 and 63 to get 36.
2x^{2}+22x+36=0
Combine -3x and 25x to get 22x.
x=\frac{-22±\sqrt{22^{2}-4\times 2\times 36}}{2\times 2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 2 for a, 22 for b, and 36 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-22±\sqrt{484-4\times 2\times 36}}{2\times 2}
Square 22.
x=\frac{-22±\sqrt{484-8\times 36}}{2\times 2}
Multiply -4 times 2.
x=\frac{-22±\sqrt{484-288}}{2\times 2}
Multiply -8 times 36.
x=\frac{-22±\sqrt{196}}{2\times 2}
Add 484 to -288.
x=\frac{-22±14}{2\times 2}
Take the square root of 196.
x=\frac{-22±14}{4}
Multiply 2 times 2.
x=-\frac{8}{4}
Now solve the equation x=\frac{-22±14}{4} when ± is plus. Add -22 to 14.
x=-2
Divide -8 by 4.
x=-\frac{36}{4}
Now solve the equation x=\frac{-22±14}{4} when ± is minus. Subtract 14 from -22.
x=-9
Divide -36 by 4.
x=-2 x=-9
The equation is now solved.
\left(3x+9\right)\left(2x-3\right)-\left(4x+12\right)x=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
Variable x cannot be equal to -3 since division by zero is not defined. Multiply both sides of the equation by 12\left(x+3\right), the least common multiple of 4,3,x+3,12.
6x^{2}+9x-27-\left(4x+12\right)x=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
Use the distributive property to multiply 3x+9 by 2x-3 and combine like terms.
6x^{2}+9x-27-\left(4x^{2}+12x\right)=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
Use the distributive property to multiply 4x+12 by x.
6x^{2}+9x-27-4x^{2}-12x=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
To find the opposite of 4x^{2}+12x, find the opposite of each term.
2x^{2}+9x-27-12x=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
Combine 6x^{2} and -4x^{2} to get 2x^{2}.
2x^{2}-3x-27=12+12\left(x+3\right)\left(-\frac{25}{12}\right)
Combine 9x and -12x to get -3x.
2x^{2}-3x-27=12-25\left(x+3\right)
Multiply 12 and -\frac{25}{12} to get -25.
2x^{2}-3x-27=12-25x-75
Use the distributive property to multiply -25 by x+3.
2x^{2}-3x-27=-63-25x
Subtract 75 from 12 to get -63.
2x^{2}-3x-27+25x=-63
Add 25x to both sides.
2x^{2}+22x-27=-63
Combine -3x and 25x to get 22x.
2x^{2}+22x=-63+27
Add 27 to both sides.
2x^{2}+22x=-36
Add -63 and 27 to get -36.
\frac{2x^{2}+22x}{2}=-\frac{36}{2}
Divide both sides by 2.
x^{2}+\frac{22}{2}x=-\frac{36}{2}
Dividing by 2 undoes the multiplication by 2.
x^{2}+11x=-\frac{36}{2}
Divide 22 by 2.
x^{2}+11x=-18
Divide -36 by 2.
x^{2}+11x+\left(\frac{11}{2}\right)^{2}=-18+\left(\frac{11}{2}\right)^{2}
Divide 11, the coefficient of the x term, by 2 to get \frac{11}{2}. Then add the square of \frac{11}{2} to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}+11x+\frac{121}{4}=-18+\frac{121}{4}
Square \frac{11}{2} by squaring both the numerator and the denominator of the fraction.
x^{2}+11x+\frac{121}{4}=\frac{49}{4}
Add -18 to \frac{121}{4}.
\left(x+\frac{11}{2}\right)^{2}=\frac{49}{4}
Factor x^{2}+11x+\frac{121}{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+\frac{11}{2}\right)^{2}}=\sqrt{\frac{49}{4}}
Take the square root of both sides of the equation.
x+\frac{11}{2}=\frac{7}{2} x+\frac{11}{2}=-\frac{7}{2}
Simplify.
x=-2 x=-9
Subtract \frac{11}{2} from both sides of the equation.