Bài 1:
a) =$\frac{27}{23}$ + $\frac{5}{21}$ - $\frac{4}{23}$ - $\frac{1}{2}$ + $\frac{58}{21}$
= $\frac{7}{2}$
b) = ($\frac{1}{2}$ - $\frac{7}{13}$ - $\frac{1}{3}$) - ($\frac{6}{13}$ + $\frac{-1}{2}$ - $\frac{4}{3}$)
= $\frac{-29}{78}$ + $\frac{107}{78}$
= 1
c) = $\frac{-1}{10}$ : ($\frac{2}{-5}$ + /$\frac{-10}{3}$/)
= $\frac{-1}{10}$ : ($\frac{2}{-5}$ + $\frac{10}{3}$)
= $\frac{-1}{10}$ : $\frac{44}{15}$
= $\frac{-1}{10}$.$\frac{15}{44}$
= $\frac{-3}{88}$
d) = $\frac{25}{2}$.($\frac{-5}{7}$) + $\frac{39}{4}$ - $\frac{40}{7}$
= $\frac{-125}{14}$ + $\frac{39}{4}$ - $\frac{40}{7}$
= $\frac{-137}{28}$
