Solve for x
x=3\sqrt{10}\approx 9.486832981
x=-3\sqrt{10}\approx -9.486832981
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x^{2}=90
Swap sides so that all variable terms are on the left hand side.
x=3\sqrt{10} x=-3\sqrt{10}
Take the square root of both sides of the equation.
x^{2}=90
Swap sides so that all variable terms are on the left hand side.
x^{2}-90=0
Subtract 90 from both sides.
x=\frac{0±\sqrt{0^{2}-4\left(-90\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -90 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-90\right)}}{2}
Square 0.
x=\frac{0±\sqrt{360}}{2}
Multiply -4 times -90.
x=\frac{0±6\sqrt{10}}{2}
Take the square root of 360.
x=3\sqrt{10}
Now solve the equation x=\frac{0±6\sqrt{10}}{2} when ± is plus.
x=-3\sqrt{10}
Now solve the equation x=\frac{0±6\sqrt{10}}{2} when ± is minus.
x=3\sqrt{10} x=-3\sqrt{10}
The equation is now solved.
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