Ответ:

а) \(\frac{6}{18}-\frac{8}{27}=\frac{1}{3}-\frac{8}{27}=\frac{9-8}{27}=\frac{1}{27}\).

б) \(\frac{7}{16}-\frac{5}{24}=\frac{21-10}{48}=\frac{11}{48}\).

в) \(\frac{2}{11}-\frac{1}{12}=\frac{24-11}{132}=\frac{13}{132}\).

г) \(\frac{12}{15}-\frac{15}{26}=\frac{4}{5}-\frac{15}{26}=\frac{104-75}{130}=\frac{29}{130}\).

д) \(\frac{9}{28}-\frac{11}{35}=\frac{45-44}{140}=\frac{1}{140}\).

е) \(\frac{39}{40}-\frac{19}{28}=\frac{273-190}{280}=\frac{83}{280}\).

Ответ: а) \(\frac{1}{27}\); б) \(\frac{11}{48}\); в) \(\frac{13}{132}\); г) \(\frac{29}{130}\); д) \(\frac{1}{140}\); е) \(\frac{83}{280}\).