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trydan


Giải phương trình sau:
[TEX] \frac{1}{1.2.3}+\frac{1}{2.3.4}+....+ \frac{1}{x(x+1)(x+2)} =\frac{637}{2550}[/TEX]
[TEX] \frac{1}{1.2.3}+\frac{1}{2.3.4}+....+ \frac{1}{x(x+1)(x+2)} =\frac{637}{2550}[/TEX]