Bài 4:
a) 3$\frac{1}{3}$ - 1$\frac{3}{4}$ = $\frac{10}{3}$ - $\frac{7}{4}$ = $\frac{40}{12}$ - $\frac{21}{12}$ = $\frac{19}{12}$
b) 2$\frac{5}{6}$ + 1$\frac{2}{3}$ = $\frac{17}{6}$ + $\frac{5}{3}$ = $\frac{17}{6}$ + $\frac{10}{6}$ = $\frac{27}{6}$ = $\frac{9}{2}$
c) 2$\frac{3}{8}$ : 1$\frac{3}{4}$ = $\frac{19}{8}$ : $\frac{7}{4}$ = $\frac{19}{8}$ x $\frac{4}{7}$ = $\frac{76}{56}$ = $\frac{19}{14}$
d) 1$\frac{3}{7}$ x 1$\frac{5}{8}$ = $\frac{10}{7}$ x $\frac{13}{8}$ = $\frac{130}{56}$ = $\frac{65}{28}$
