Solve for x
x=2\sqrt{3}\approx 3.464101615
x=-2\sqrt{3}\approx -3.464101615
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x^{2}-4=8
Calculate 2 to the power of 2 and get 4.
x^{2}=8+4
Add 4 to both sides.
x^{2}=12
Add 8 and 4 to get 12.
x=2\sqrt{3} x=-2\sqrt{3}
Take the square root of both sides of the equation.
x^{2}-4=8
Calculate 2 to the power of 2 and get 4.
x^{2}-4-8=0
Subtract 8 from both sides.
x^{2}-12=0
Subtract 8 from -4 to get -12.
x=\frac{0±\sqrt{0^{2}-4\left(-12\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -12 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-12\right)}}{2}
Square 0.
x=\frac{0±\sqrt{48}}{2}
Multiply -4 times -12.
x=\frac{0±4\sqrt{3}}{2}
Take the square root of 48.
x=2\sqrt{3}
Now solve the equation x=\frac{0±4\sqrt{3}}{2} when ± is plus.
x=-2\sqrt{3}
Now solve the equation x=\frac{0±4\sqrt{3}}{2} when ± is minus.
x=2\sqrt{3} x=-2\sqrt{3}
The equation is now solved.
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