10.2. Solve the equation: $\sqrt[3]{20-x}-\sqrt[3]{13-x}=\sqrt[3]{7}$.
Answer: 20 and 13.

Solution. If everything is simply raised to the cube and like terms are combined, we get $\sqrt[3]{20-x} \sqrt[3]{13-x}(\sqrt[3]{20-x}-\sqrt[3]{13-x})=0$. The bracket is not equal to 0, so either $x=20$ or $x=13$.

Evaluation. Just the answer with verification: 1 point. Loss of a solution - minus 3 points.