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Solve for x (complex solution)
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5=-2\left(x^{2}+99\right)+23
Add -22 and 121 to get 99.
5=-2x^{2}-198+23
Use the distributive property to multiply -2 by x^{2}+99.
5=-2x^{2}-175
Add -198 and 23 to get -175.
-2x^{2}-175=5
Swap sides so that all variable terms are on the left hand side.
-2x^{2}=5+175
Add 175 to both sides.
-2x^{2}=180
Add 5 and 175 to get 180.
x^{2}=\frac{180}{-2}
Divide both sides by -2.
x^{2}=-90
Divide 180 by -2 to get -90.
x=3\sqrt{10}i x=-3\sqrt{10}i
The equation is now solved.
5=-2\left(x^{2}+99\right)+23
Add -22 and 121 to get 99.
5=-2x^{2}-198+23
Use the distributive property to multiply -2 by x^{2}+99.
5=-2x^{2}-175
Add -198 and 23 to get -175.
-2x^{2}-175=5
Swap sides so that all variable terms are on the left hand side.
-2x^{2}-175-5=0
Subtract 5 from both sides.
-2x^{2}-180=0
Subtract 5 from -175 to get -180.
x=\frac{0±\sqrt{0^{2}-4\left(-2\right)\left(-180\right)}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, 0 for b, and -180 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-2\right)\left(-180\right)}}{2\left(-2\right)}
Square 0.
x=\frac{0±\sqrt{8\left(-180\right)}}{2\left(-2\right)}
Multiply -4 times -2.
x=\frac{0±\sqrt{-1440}}{2\left(-2\right)}
Multiply 8 times -180.
x=\frac{0±12\sqrt{10}i}{2\left(-2\right)}
Take the square root of -1440.
x=\frac{0±12\sqrt{10}i}{-4}
Multiply 2 times -2.
x=-3\sqrt{10}i
Now solve the equation x=\frac{0±12\sqrt{10}i}{-4} when ± is plus.
x=3\sqrt{10}i
Now solve the equation x=\frac{0±12\sqrt{10}i}{-4} when ± is minus.
x=-3\sqrt{10}i x=3\sqrt{10}i
The equation is now solved.