999999999999999999999999999999999999999999999 sờ
chứng minh nếu $a,b,c>0$ và$\frac{1}{a+1}+\frac{1}{b+1}+\frac{1}{c+1}+\frac{1}{d+1}\geq 3$ thì $abcd\leq \frac{1}{
81}$
Bất đẳng thức
999999999999999999999999999999999999999999999 sờ
chứng minh nếu $a,b,c>0$ và$\frac{1}{a+1}+\frac{1}{b+1}+\frac{1}{c+1}+\frac{1}{d+1}\geq 3$ thì $abcd\leq \frac{1}{1
6}$
Bất đẳng thức
999999999999999999999999999999999999999999999 sờ
chứng minh nếu $a,b,c>0$ và$\frac{1}{a+1}+\frac{1}{b+1}+\frac{1}{c+1}+\frac{1}{d+1}\geq 3$ thì $abcd\leq \frac{1}{
81}$
Bất đẳng thức