a) MSC: 15
QĐ:
$\frac{3}{5}$ = $\frac{9}{15}$
$\frac{5}{3}$ = $\frac{25}{15}$
Vì $\frac{9}{15}$ < $\frac{25}{15}$ ⇒ $\frac{3}{5}$ < $\frac{5}{3}$
b) $\frac{5}{-13}$ = $\frac{-5}{13}$
MSC: 65
QĐ:
$\frac{-3}{5}$ = $\frac{-39}{65}$
$\frac{-5}{13}$ = $\frac{-25}{65}$
Vì $\frac{-39}{65}$ < $\frac{-25}{65}$ ⇒ $\frac{-3}{5}$ < $\frac{5}{-13}$