Skip to main content
Solve for x
Tick mark Image
Graph

Similar Problems from Web Search

Share

-12x^{2}=-8
Subtract 8 from both sides. Anything subtracted from zero gives its negation.
x^{2}=\frac{-8}{-12}
Divide both sides by -12.
x^{2}=\frac{2}{3}
Reduce the fraction \frac{-8}{-12} to lowest terms by extracting and canceling out -4.
x=\frac{\sqrt{6}}{3} x=-\frac{\sqrt{6}}{3}
Take the square root of both sides of the equation.
-12x^{2}+8=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(-12\right)\times 8}}{2\left(-12\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -12 for a, 0 for b, and 8 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
x=\frac{0±\sqrt{-4\left(-12\right)\times 8}}{2\left(-12\right)}
Square 0.
x=\frac{0±\sqrt{48\times 8}}{2\left(-12\right)}
Multiply -4 times -12.
x=\frac{0±\sqrt{384}}{2\left(-12\right)}
Multiply 48 times 8.
x=\frac{0±8\sqrt{6}}{2\left(-12\right)}
Take the square root of 384.
x=\frac{0±8\sqrt{6}}{-24}
Multiply 2 times -12.
x=-\frac{\sqrt{6}}{3}
Now solve the equation x=\frac{0±8\sqrt{6}}{-24} when ± is plus.
x=\frac{\sqrt{6}}{3}
Now solve the equation x=\frac{0±8\sqrt{6}}{-24} when ± is minus.
x=-\frac{\sqrt{6}}{3} x=\frac{\sqrt{6}}{3}
The equation is now solved.