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x^{2}-4=0
Multiply both sides by 2.
\left(x-2\right)\left(x+2\right)=0
Consider x^{2}-4. Rewrite x^{2}-4 as x^{2}-2^{2}. The difference of squares can be factored using the rule: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right).
x=2 x=-2
To find equation solutions, solve x-2=0 and x+2=0.
\frac{1}{2}x^{2}=2
Add 2 to both sides. Anything plus zero gives itself.
x^{2}=2\times 2
Multiply both sides by 2, the reciprocal of \frac{1}{2}.
x^{2}=4
Multiply 2 and 2 to get 4.
x=2 x=-2
Take the square root of both sides of the equation.
\frac{1}{2}x^{2}-2=0
Quadratic equations like this one, with an x^{2} term but no x term, can still be solved using the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}, once they are put in standard form: ax^{2}+bx+c=0.
x=\frac{0±\sqrt{0^{2}-4\times \frac{1}{2}\left(-2\right)}}{2\times \frac{1}{2}}
This equation is in standard form: ax^{2}+bx+c=0. Substitute \frac{1}{2} for a, 0 for b, and -2 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times \frac{1}{2}\left(-2\right)}}{2\times \frac{1}{2}}
Square 0.
x=\frac{0±\sqrt{-2\left(-2\right)}}{2\times \frac{1}{2}}
Multiply -4 times \frac{1}{2}.
x=\frac{0±\sqrt{4}}{2\times \frac{1}{2}}
Multiply -2 times -2.
x=\frac{0±2}{2\times \frac{1}{2}}
Take the square root of 4.
x=\frac{0±2}{1}
Multiply 2 times \frac{1}{2}.
x=2
Now solve the equation x=\frac{0±2}{1} when ± is plus.
x=-2
Now solve the equation x=\frac{0±2}{1} when ± is minus.
x=2 x=-2
The equation is now solved.