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4x^{2}-9=0
Multiply both sides by 12.
\left(2x-3\right)\left(2x+3\right)=0
Consider 4x^{2}-9. Rewrite 4x^{2}-9 as \left(2x\right)^{2}-3^{2}. The difference of squares can be factored using the rule: a^{2}-b^{2}=\left(a-b\right)\left(a+b\right).
x=\frac{3}{2} x=-\frac{3}{2}
To find equation solutions, solve 2x-3=0 and 2x+3=0.
\frac{1}{3}x^{2}=\frac{3}{4}
Add \frac{3}{4} to both sides. Anything plus zero gives itself.
x^{2}=\frac{3}{4}\times 3
Multiply both sides by 3, the reciprocal of \frac{1}{3}.
x^{2}=\frac{9}{4}
Multiply \frac{3}{4} and 3 to get \frac{9}{4}.
x=\frac{3}{2} x=-\frac{3}{2}
Take the square root of both sides of the equation.
\frac{1}{3}x^{2}-\frac{3}{4}=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}{3}\left(-\frac{3}{4}\right)}}{2\times \frac{1}{3}}
This equation is in standard form: ax^{2}+bx+c=0. Substitute \frac{1}{3} for a, 0 for b, and -\frac{3}{4} for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\times \frac{1}{3}\left(-\frac{3}{4}\right)}}{2\times \frac{1}{3}}
Square 0.
x=\frac{0±\sqrt{-\frac{4}{3}\left(-\frac{3}{4}\right)}}{2\times \frac{1}{3}}
Multiply -4 times \frac{1}{3}.
x=\frac{0±\sqrt{1}}{2\times \frac{1}{3}}
Multiply -\frac{4}{3} times -\frac{3}{4} by multiplying numerator times numerator and denominator times denominator. Then reduce the fraction to lowest terms if possible.
x=\frac{0±1}{2\times \frac{1}{3}}
Take the square root of 1.
x=\frac{0±1}{\frac{2}{3}}
Multiply 2 times \frac{1}{3}.
x=\frac{3}{2}
Now solve the equation x=\frac{0±1}{\frac{2}{3}} when ± is plus. Divide 1 by \frac{2}{3} by multiplying 1 by the reciprocal of \frac{2}{3}.
x=-\frac{3}{2}
Now solve the equation x=\frac{0±1}{\frac{2}{3}} when ± is minus. Divide -1 by \frac{2}{3} by multiplying -1 by the reciprocal of \frac{2}{3}.
x=\frac{3}{2} x=-\frac{3}{2}
The equation is now solved.