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Solve for x (complex solution)
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2x^{2}=-10
Subtract 10 from both sides. Anything subtracted from zero gives its negation.
x^{2}=\frac{-10}{2}
Divide both sides by 2.
x^{2}=-5
Divide -10 by 2 to get -5.
x=\sqrt{5}i x=-\sqrt{5}i
The equation is now solved.
2x^{2}+10=0
Quadratic equations like this one, with an x^{2} term but no x term, can still be solved using the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}, once they are put in standard form: ax^{2}+bx+c=0.
x=\frac{0±\sqrt{0^{2}-4\times 2\times 10}}{2\times 2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 2 for a, 0 for b, and 10 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 2\times 10}}{2\times 2}
Square 0.
x=\frac{0±\sqrt{-8\times 10}}{2\times 2}
Multiply -4 times 2.
x=\frac{0±\sqrt{-80}}{2\times 2}
Multiply -8 times 10.
x=\frac{0±4\sqrt{5}i}{2\times 2}
Take the square root of -80.
x=\frac{0±4\sqrt{5}i}{4}
Multiply 2 times 2.
x=\sqrt{5}i
Now solve the equation x=\frac{0±4\sqrt{5}i}{4} when ± is plus.
x=-\sqrt{5}i
Now solve the equation x=\frac{0±4\sqrt{5}i}{4} when ± is minus.
x=\sqrt{5}i x=-\sqrt{5}i
The equation is now solved.