1 .Cho $\alpha \geq \beta \geq \gamma > 0 ,x\geq \alpha ;y\geq \beta ;z\geq \gamma$
Tìm Min P=x+y+z
2. Cho $0 < \alpha \leq \beta \leq \gamma ;x\leq y\leq z;z\leq \gamma ;yz\leq \gamma \beta ;xyz\leq \alpha \beta \gamma$
Tìm Max P=x+y+z
3. Cho $\alpha \geq \beta \geq \gamma > 0; z\leq \gamma ;\frac{y}{\beta }+\frac{z}{\gamma }\leq 2;\frac{x}{\alpha }+\frac{y}{\beta }+\frac{z}{\gamma }\leq 3$
Tìm Min P=$\frac{1}{x}+\frac{1}{y}+\frac{1}{z}$