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daodung28


tìm x,y,z thoả mãn(hệ đấy nhá)
[TEX] \left\ {\begin{\frac{1}{x}+\frac{1}{y}+\frac{1}{z}+x+y+z=\frac{51}{4}}\\ {\frac{1}{x^2}+\frac{1}{y^2}+\frac{1}{z^2}+x^2+y^2+z^2=\frac{771}{16}}[/TEX]
[TEX] \left\ {\begin{\frac{1}{x}+\frac{1}{y}+\frac{1}{z}+x+y+z=\frac{51}{4}}\\ {\frac{1}{x^2}+\frac{1}{y^2}+\frac{1}{z^2}+x^2+y^2+z^2=\frac{771}{16}}[/TEX]