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x^{2}-2x-2=4
Multiply both sides of the equation by 4, the least common multiple of 4,2.
x^{2}-2x-2-4=0
Subtract 4 from both sides.
x^{2}-2x-6=0
Subtract 4 from -2 to get -6.
x=\frac{-\left(-2\right)±\sqrt{\left(-2\right)^{2}-4\left(-6\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, -2 for b, and -6 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{-\left(-2\right)±\sqrt{4-4\left(-6\right)}}{2}
Square -2.
x=\frac{-\left(-2\right)±\sqrt{4+24}}{2}
Multiply -4 times -6.
x=\frac{-\left(-2\right)±\sqrt{28}}{2}
Add 4 to 24.
x=\frac{-\left(-2\right)±2\sqrt{7}}{2}
Take the square root of 28.
x=\frac{2±2\sqrt{7}}{2}
The opposite of -2 is 2.
x=\frac{2\sqrt{7}+2}{2}
Now solve the equation x=\frac{2±2\sqrt{7}}{2} when ± is plus. Add 2 to 2\sqrt{7}.
x=\sqrt{7}+1
Divide 2+2\sqrt{7} by 2.
x=\frac{2-2\sqrt{7}}{2}
Now solve the equation x=\frac{2±2\sqrt{7}}{2} when ± is minus. Subtract 2\sqrt{7} from 2.
x=1-\sqrt{7}
Divide 2-2\sqrt{7} by 2.
x=\sqrt{7}+1 x=1-\sqrt{7}
The equation is now solved.
x^{2}-2x-2=4
Multiply both sides of the equation by 4, the least common multiple of 4,2.
x^{2}-2x=4+2
Add 2 to both sides.
x^{2}-2x=6
Add 4 and 2 to get 6.
x^{2}-2x+1=6+1
Divide -2, the coefficient of the x term, by 2 to get -1. Then add the square of -1 to both sides of the equation. This step makes the left hand side of the equation a perfect square.
x^{2}-2x+1=7
Add 6 to 1.
\left(x-1\right)^{2}=7
Factor x^{2}-2x+1. In general, when x^{2}+bx+c is a perfect square, it can always be factored as \left(x+\frac{b}{2}\right)^{2}.
\sqrt{\left(x-1\right)^{2}}=\sqrt{7}
Take the square root of both sides of the equation.
x-1=\sqrt{7} x-1=-\sqrt{7}
Simplify.
x=\sqrt{7}+1 x=1-\sqrt{7}
Add 1 to both sides of the equation.