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6x^{2}-17ix-12=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{17i±\sqrt{\left(-17i\right)^{2}-4\times 6\left(-12\right)}}{2\times 6}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 6 for a, -17i for b, and -12 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{17i±\sqrt{-289-4\times 6\left(-12\right)}}{2\times 6}
Square -17i.
x=\frac{17i±\sqrt{-289-24\left(-12\right)}}{2\times 6}
Multiply -4 times 6.
x=\frac{17i±\sqrt{-289+288}}{2\times 6}
Multiply -24 times -12.
x=\frac{17i±\sqrt{-1}}{2\times 6}
Add -289 to 288.
x=\frac{17i±i}{2\times 6}
Take the square root of -1.
x=\frac{17i±i}{12}
Multiply 2 times 6.
x=\frac{18i}{12}
Now solve the equation x=\frac{17i±i}{12} when ± is plus. Add 17i to i.
x=\frac{3}{2}i
Divide 18i by 12.
x=\frac{16i}{12}
Now solve the equation x=\frac{17i±i}{12} when ± is minus. Subtract i from 17i.
x=\frac{4}{3}i
Divide 16i by 12.
x=\frac{3}{2}i x=\frac{4}{3}i
The equation is now solved.
6x^{2}-17ix-12=0
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.
6x^{2}-17ix-12-\left(-12\right)=-\left(-12\right)
Add 12 to both sides of the equation.
6x^{2}-17ix=-\left(-12\right)
Subtracting -12 from itself leaves 0.
6x^{2}-17ix=12
Subtract -12 from 0.
\frac{6x^{2}-17ix}{6}=\frac{12}{6}
Divide both sides by 6.
x^{2}+\frac{-17i}{6}x=\frac{12}{6}
Dividing by 6 undoes the multiplication by 6.
x^{2}-\frac{17}{6}ix=\frac{12}{6}
Divide -17i by 6.
x^{2}-\frac{17}{6}ix=2
Divide 12 by 6.
x^{2}-\frac{17}{6}ix+\left(-\frac{17}{12}i\right)^{2}=2+\left(-\frac{17}{12}i\right)^{2}
Divide -\frac{17}{6}i, the coefficient of the x term, by 2 to get -\frac{17}{12}i. Then add the square of -\frac{17}{12}i to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-\frac{17}{6}ix-\frac{289}{144}=2-\frac{289}{144}
Square -\frac{17}{12}i.
x^{2}-\frac{17}{6}ix-\frac{289}{144}=-\frac{1}{144}
Add 2 to -\frac{289}{144}.
\left(x-\frac{17}{12}i\right)^{2}=-\frac{1}{144}
Factor x^{2}-\frac{17}{6}ix-\frac{289}{144}. 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{17}{12}i\right)^{2}}=\sqrt{-\frac{1}{144}}
Take the square root of both sides of the equation.
x-\frac{17}{12}i=\frac{1}{12}i x-\frac{17}{12}i=-\frac{1}{12}i
Simplify.
x=\frac{3}{2}i x=\frac{4}{3}i
Add \frac{17}{12}i to both sides of the equation.