Solve for x
x=\frac{2\sqrt{6}}{9}\approx 0.544331054
x=-\frac{2\sqrt{6}}{9}\approx -0.544331054
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\frac{9}{4}x^{2}=\frac{2}{3}
Add \frac{2}{3} to both sides. Anything plus zero gives itself.
x^{2}=\frac{2}{3}\times \frac{4}{9}
Multiply both sides by \frac{4}{9}, the reciprocal of \frac{9}{4}.
x^{2}=\frac{8}{27}
Multiply \frac{2}{3} and \frac{4}{9} to get \frac{8}{27}.
x=\frac{2\sqrt{6}}{9} x=-\frac{2\sqrt{6}}{9}
Take the square root of both sides of the equation.
\frac{9}{4}x^{2}-\frac{2}{3}=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{9}{4}\left(-\frac{2}{3}\right)}}{2\times \frac{9}{4}}
This equation is in standard form: ax^{2}+bx+c=0. Substitute \frac{9}{4} for a, 0 for b, and -\frac{2}{3} for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times \frac{9}{4}\left(-\frac{2}{3}\right)}}{2\times \frac{9}{4}}
Square 0.
x=\frac{0±\sqrt{-9\left(-\frac{2}{3}\right)}}{2\times \frac{9}{4}}
Multiply -4 times \frac{9}{4}.
x=\frac{0±\sqrt{6}}{2\times \frac{9}{4}}
Multiply -9 times -\frac{2}{3}.
x=\frac{0±\sqrt{6}}{\frac{9}{2}}
Multiply 2 times \frac{9}{4}.
x=\frac{2\sqrt{6}}{9}
Now solve the equation x=\frac{0±\sqrt{6}}{\frac{9}{2}} when ± is plus.
x=-\frac{2\sqrt{6}}{9}
Now solve the equation x=\frac{0±\sqrt{6}}{\frac{9}{2}} when ± is minus.
x=\frac{2\sqrt{6}}{9} x=-\frac{2\sqrt{6}}{9}
The equation is now solved.
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