a: \(\Leftrightarrow\sqrt[3]{x}\cdot10-\sqrt[3]{x}\cdot4-\sqrt[3]{x}\cdot3=15\)
\(\Leftrightarrow3\sqrt[3]{x}=15\)
=>x=125
b: \(\Leftrightarrow\sqrt[3]{x-3}=x-3\)
\(\Leftrightarrow\left(x-3\right)=\left(x-3\right)^3\)
\(\Leftrightarrow\left(x-3\right)\left(x-2\right)\left(x-4\right)=0\)
hay \(x\in\left\{3;2;4\right\}\)