a) Ta có: \(\frac{39}{-65}=\frac{-39}{65}=\frac{\left(-39\right):13}{65:13}=\frac{-3}{5}\)
Vậy \(\frac{-3}{5}=\frac{39}{-65}\)
b) Ta có: \(\frac{-9}{27}=\frac{\left(-9\right):9}{27:9}=\frac{-1}{3}\)
\(\frac{-41}{123}=\frac{\left(-41\right):41}{123:41}=\frac{-1}{3}\)
Vậy \(\frac{-9}{27}=\frac{-41}{123}\)
c) MSC = 20
Ta có: \(\frac{-3}{4}=\frac{\left(-3\right).5}{4.5}=\frac{-15}{20}\)
\(\frac{4}{-5}=\frac{-4}{5}=\frac{\left(-4\right).4}{4.5}=\frac{-16}{20}\)
Vì -15 > -16 \(\Rightarrow\frac{-3}{4}>\frac{-4}{5}\)
d) MSC = 21
Ta có: \(\frac{-2}{3}=\frac{\left(-2\right).7}{3.7}=\frac{-14}{21}\)
\(\frac{-5}{7}=\frac{\left(-5\right).3}{7.3}=\frac{-15}{21}\)
Vì -14 > -15 \(\Rightarrow\frac{-2}{3}>\frac{5}{7}\)
