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-100x^{2}=-25
Subtract 25 from both sides. Anything subtracted from zero gives its negation.
x^{2}=\frac{-25}{-100}
Divide both sides by -100.
x^{2}=\frac{1}{4}
Reduce the fraction \frac{-25}{-100} to lowest terms by extracting and canceling out -25.
x=\frac{1}{2} x=-\frac{1}{2}
Take the square root of both sides of the equation.
-100x^{2}+25=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\left(-100\right)\times 25}}{2\left(-100\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -100 for a, 0 for b, and 25 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-100\right)\times 25}}{2\left(-100\right)}
Square 0.
x=\frac{0±\sqrt{400\times 25}}{2\left(-100\right)}
Multiply -4 times -100.
x=\frac{0±\sqrt{10000}}{2\left(-100\right)}
Multiply 400 times 25.
x=\frac{0±100}{2\left(-100\right)}
Take the square root of 10000.
x=\frac{0±100}{-200}
Multiply 2 times -100.
x=-\frac{1}{2}
Now solve the equation x=\frac{0±100}{-200} when ± is plus. Reduce the fraction \frac{100}{-200} to lowest terms by extracting and canceling out 100.
x=\frac{1}{2}
Now solve the equation x=\frac{0±100}{-200} when ± is minus. Reduce the fraction \frac{-100}{-200} to lowest terms by extracting and canceling out 100.
x=-\frac{1}{2} x=\frac{1}{2}
The equation is now solved.