D
dotriduong


Cho [TEX]a+b+c+d+e=1[/TEX] và [TEX]0 \leq a \leq b \leq c \leq d \leq e[/TEX]
C/M : [TEX]a(bc+be+cd+de)+cd(b+e+a) \leq \frac{1}{25}[/TEX]
C/M : [TEX]a(bc+be+cd+de)+cd(b+e+a) \leq \frac{1}{25}[/TEX]
Last edited by a moderator: