Solve for x (complex solution)
x=-\sqrt{15}i\approx -0-3.872983346i
x=\sqrt{15}i\approx 3.872983346i
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0=x^{2}+9+2\times 3
Calculate 3 to the power of 2 and get 9.
0=x^{2}+9+6
Multiply 2 and 3 to get 6.
0=x^{2}+15
Add 9 and 6 to get 15.
x^{2}+15=0
Swap sides so that all variable terms are on the left hand side.
x^{2}=-15
Subtract 15 from both sides. Anything subtracted from zero gives its negation.
x=\sqrt{15}i x=-\sqrt{15}i
The equation is now solved.
0=x^{2}+9+2\times 3
Calculate 3 to the power of 2 and get 9.
0=x^{2}+9+6
Multiply 2 and 3 to get 6.
0=x^{2}+15
Add 9 and 6 to get 15.
x^{2}+15=0
Swap sides so that all variable terms are on the left hand side.
x=\frac{0±\sqrt{0^{2}-4\times 15}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and 15 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 15}}{2}
Square 0.
x=\frac{0±\sqrt{-60}}{2}
Multiply -4 times 15.
x=\frac{0±2\sqrt{15}i}{2}
Take the square root of -60.
x=\sqrt{15}i
Now solve the equation x=\frac{0±2\sqrt{15}i}{2} when ± is plus.
x=-\sqrt{15}i
Now solve the equation x=\frac{0±2\sqrt{15}i}{2} when ± is minus.
x=\sqrt{15}i x=-\sqrt{15}i
The equation is now solved.
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