firetiger06

Câu 1

Cho $x> 1/3 ,  y> 1/2 , z > 1$

 $\frac{3}{3x+2}+\frac{2}{2y+1}+\frac{1}{z}\geq 2$
Tim max : (3x-1)(2y-1)(z-1)

Câu 2 : x,y,z $\geq$0 t/m : $\sqrt{1+x^{2}}+\sqrt{1+2y}+\sqrt{1+2z}=5$
Max P = 2(x³+y³) + z³

Câu 3 : a,b,c > 0. Chứng minh :
$\frac{1}{a(b+1)}+\frac{1}{b(c+1)}+\frac{1}{c(a+1)}\geq \frac{3}{\sqrt[3]{abc}(1+\sqrt[3]{abc})}$