Đáp án:
a) `\frac{5}{3} = \frac{5.3}{3.3} = \frac{15}{9}.`
b) `\frac{3}{14} = \frac{3.3}{14.3} = \frac{9}{42}`
`\frac{5}{6} = \frac{5.7}{6.7} = \frac{35}{42}`
c) `\frac{-2}{25} = \frac{-2.7}{25.7} = \frac{-14}{175}`
`\frac{3}{-35} = \frac{-3}{35} = \frac{-3.5}{35.5} = \frac{-15}{175}`
Chúc học tốt!!!