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r^{2}=24
Add 24 to both sides. Anything plus zero gives itself.
r=2\sqrt{6} r=-2\sqrt{6}
Take the square root of both sides of the equation.
r^{2}-24=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.
r=\frac{0±\sqrt{0^{2}-4\left(-24\right)}}{2}
This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and -24 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
r=\frac{0±\sqrt{-4\left(-24\right)}}{2}
Square 0.
r=\frac{0±\sqrt{96}}{2}
Multiply -4 times -24.
r=\frac{0±4\sqrt{6}}{2}
Take the square root of 96.
r=2\sqrt{6}
Now solve the equation r=\frac{0±4\sqrt{6}}{2} when ± is plus.
r=-2\sqrt{6}
Now solve the equation r=\frac{0±4\sqrt{6}}{2} when ± is minus.
r=2\sqrt{6} r=-2\sqrt{6}
The equation is now solved.