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tieuphong_1802


Cho x,y,z>0. C/m rằng
[TEX]3({x}^{2}y+{y}^{2}z+{z}^{2}x)(x{y}^{2}+y{z}^{2}+z{x}^{2})\geq xyz({x+y+z})^{3}[/TEX]
[TEX]3({x}^{2}y+{y}^{2}z+{z}^{2}x)(x{y}^{2}+y{z}^{2}+z{x}^{2})\geq xyz({x+y+z})^{3}[/TEX]