K
kienduc_vatli


1. cho a,b,c >0 , a+b+c =3 . tìm GTNN $A=\frac{a^2}{b+c}+\frac{b^2}{a+c}+\frac{c^2}{a+c}$
2. cho a.b,c >0 . abc=1
cm $\frac{a^3}{a^2+ab+b^2}$\geq $\frac{2a-b}{3}$
2. cho a.b,c >0 . abc=1
cm $\frac{a^3}{a^2+ab+b^2}$\geq $\frac{2a-b}{3}$