Solve for x (complex solution)
x=-\sqrt{21}i\approx -0-4.582575695i
x=\sqrt{21}i\approx 4.582575695i
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x^{2}+121=10^{2}
Calculate 11 to the power of 2 and get 121.
x^{2}+121=100
Calculate 10 to the power of 2 and get 100.
x^{2}=100-121
Subtract 121 from both sides.
x^{2}=-21
Subtract 121 from 100 to get -21.
x=\sqrt{21}i x=-\sqrt{21}i
The equation is now solved.
x^{2}+121=10^{2}
Calculate 11 to the power of 2 and get 121.
x^{2}+121=100
Calculate 10 to the power of 2 and get 100.
x^{2}+121-100=0
Subtract 100 from both sides.
x^{2}+21=0
Subtract 100 from 121 to get 21.
x=\frac{0±\sqrt{0^{2}-4\times 21}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and 21 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times 21}}{2}
Square 0.
x=\frac{0±\sqrt{-84}}{2}
Multiply -4 times 21.
x=\frac{0±2\sqrt{21}i}{2}
Take the square root of -84.
x=\sqrt{21}i
Now solve the equation x=\frac{0±2\sqrt{21}i}{2} when ± is plus.
x=-\sqrt{21}i
Now solve the equation x=\frac{0±2\sqrt{21}i}{2} when ± is minus.
x=\sqrt{21}i x=-\sqrt{21}i
The equation is now solved.
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