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8+2a^{2}=4a^{2}
Multiply both sides of the equation by 4.
8+2a^{2}-4a^{2}=0
Subtract 4a^{2} from both sides.
8-2a^{2}=0
Combine 2a^{2} and -4a^{2} to get -2a^{2}.
-2a^{2}=-8
Subtract 8 from both sides. Anything subtracted from zero gives its negation.
a^{2}=\frac{-8}{-2}
Divide both sides by -2.
a^{2}=4
Divide -8 by -2 to get 4.
a=2 a=-2
Take the square root of both sides of the equation.
8+2a^{2}=4a^{2}
Multiply both sides of the equation by 4.
8+2a^{2}-4a^{2}=0
Subtract 4a^{2} from both sides.
8-2a^{2}=0
Combine 2a^{2} and -4a^{2} to get -2a^{2}.
-2a^{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.
a=\frac{0±\sqrt{0^{2}-4\left(-2\right)\times 8}}{2\left(-2\right)}
This equation is in standard form: ax^{2}+bx+c=0. Substitute -2 for a, 0 for b, and 8 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.
a=\frac{0±\sqrt{-4\left(-2\right)\times 8}}{2\left(-2\right)}
Square 0.
a=\frac{0±\sqrt{8\times 8}}{2\left(-2\right)}
Multiply -4 times -2.
a=\frac{0±\sqrt{64}}{2\left(-2\right)}
Multiply 8 times 8.
a=\frac{0±8}{2\left(-2\right)}
Take the square root of 64.
a=\frac{0±8}{-4}
Multiply 2 times -2.
a=-2
Now solve the equation a=\frac{0±8}{-4} when ± is plus. Divide 8 by -4.
a=2
Now solve the equation a=\frac{0±8}{-4} when ± is minus. Divide -8 by -4.
a=-2 a=2
The equation is now solved.