Vyřešit aleq3cu

$$a \leq 3 c u$$

Vyřešit pro: u

$$\left\{\begin{matrix}u\geq \frac{a}{3c}\text{, }&c>0\\u\in \mathrm{R}\text{, }&a\leq 0\text{ and }c=0\\u=\frac{a}{3c}\text{, }&a\leq 0\text{ or }c\neq 0\\u\leq \frac{a}{3c}\text{, }&c<0\end{matrix}\right,$$

Vyřešit pro: c

$$\left\{\begin{matrix}c\geq \frac{a}{3u}\text{, }&u>0\\c\in \mathrm{R}\text{, }&a\leq 0\text{ and }u=0\\c=\frac{a}{3u}\text{, }&a\leq 0\text{ or }u\neq 0\\c\leq \frac{a}{3u}\text{, }&u<0\end{matrix}\right,$$