Đáp án:

 $a) 
\frac{1}{11}\\
\frac{-66}{11}\\
b)
\frac{13}{120}
\frac{21}{120}\\
c)
\frac{91}{949}\\
\frac{438}{949}\\
d) \frac{-84}{360}\\
\frac{78}{360}\\
\frac{-81}{360}
e) 
\frac{-51}{180}\\
\frac{-50}{180}\\
\frac{128}{180}$

Giải thích các bước giải:

$a) MSC=11\\
\frac{1}{11}\\
-6=\frac{(-6).11}{11}=\frac{-66}{11}\\
b)
MSC=120 \\
\frac{13}{120}
\frac{7}{40}=\frac{7.3}{40.3}=\frac{21}{120}\\
c)
MSC=73.13=949\\
\frac{14}{146}=\frac{7}{73}=\frac{7.13}{73.13}=\frac{91}{949}\\
\frac{6}{13}=\frac{6.73}{13.73}=\frac{438}{949}\\
d) MSC=360\\
\frac{-7}{30}=\frac{(-7).12}{30.12}=\frac{-84}{360}\\
\frac{13}{60}=\frac{13.6}{60.6}=\frac{78}{360}\\
\frac{-9}{40}=\frac{(-9).9}{40.9}=\frac{-81}{360}
e) 
MSC=180\\
\frac{-17}{60}=\frac{(-17).3}{60.3}=\frac{-51}{180}\\
\frac{-5}{18}=\frac{(-5).10}{18.10}=\frac{-50}{180}\\
\frac{64}{90}=\frac{64.2}{90.2}=\frac{128}{180}$