Đáp án:
$\frac{35}{198}$ + $\frac{5}{18}$ - $\frac{7}{36}$ +$\frac{9}{60}$ - $\frac{11}{90}$ + ...... + $\frac{63}{2976}$ - $\frac{65}{3168}$
= ( $\frac{35}{198}$ + $\frac{5}{18}$ ) - ($\frac{7}{36}$ + $\frac{9}{60}$ - $\frac{11}{90}$
= $\frac{5}{11}$ - $\frac{31}{90}$ - $\frac{11}{90}$
= $\frac{-2 }{165}$
= $\frac{63 }{2976}$ - $\frac{65 }{3168}$
=$\frac{ 0.00065167807}{0.00065167807}$ =1
= $\frac{161 }{558}$
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