Answer
$-\frac{2}{3}$ and $\frac{2}{3}$
Work Step by Step
Solve the equation by taking the fourth root of both sides:
$x \pm \sqrt[4]{\frac{16}{81}}
\\x = \pm \sqrt[4]{\left(\frac{2}{3}\right)^4}
\\x = \pm \frac{2}{3}.$
Thus, the two real solutions of the given equation are $-\frac{2}{3}$ and $\frac{2}{3}$.
