2/9+6/9-3/9 , 8 25/7-(3 8/27+2 3/27) , (8 3/17-7 15/17)+3 16/17 , 3/5-4/7 , 4/9+4/27 , 7/12-3/20 .

\( \frac{2}{9} + \frac{6}{9} - \frac{3}{9} = \frac{5}{9} \)

\( 8 \frac{25}{7} - (3 \frac{8}{27} + 2 \frac{3}{27}) = 8 \frac{5}{7} \)

\( (8 \frac{3}{17} - 7 \frac{15}{17}) + 3 \frac{16}{17} = 4 \frac{1}{17} \)

\( \frac{3}{5} - \frac{4}{7} = \frac{1}{35} \)

\( \frac{4}{9} + \frac{4}{27} = \frac{16}{27} \)

\( \frac{7}{12} - \frac{3}{20} = \frac{17}{60} \)