Tìm x,

- Hướng dẫn giải

Chú ý rằng:

- Nếu $a^2=b^2$ thì a = b hoặc x = -b

 Nếu $a^3=b^3$ thì a = b

$\begin{array}{l}a)x\in \left\{\frac{3}{2};\frac{5}{2}\right\}\\ \\ b)x\in \left\{\frac{-10}{3};\frac{8}{3}\right\}\\ \\ c)x\in \left\{\frac{-2}{5};\frac{4}{5}\right\}\\ \\ d)x=\frac{1}{27}\end{array}$