1: \(\dfrac{3}{-7}=\dfrac{-3}{7}=\dfrac{-3\cdot30}{7\cdot30}=\dfrac{-90}{210}\)
\(\dfrac{9}{21}=\dfrac{9\cdot10}{21\cdot10}=\dfrac{90}{210}\)
\(\dfrac{-6}{35}=\dfrac{-6\cdot6}{35\cdot6}=\dfrac{-36}{210}\)
2: \(\dfrac{-4}{15}=\dfrac{-4\cdot36}{15\cdot36}=\dfrac{-144}{540}\)
\(\dfrac{-7}{12}=\dfrac{-7\cdot45}{12\cdot45}=\dfrac{-315}{540}\)
\(\dfrac{8}{27}=\dfrac{8\cdot20}{27\cdot20}=\dfrac{160}{540}\)
3: \(\dfrac{-5}{16}=\dfrac{-5\cdot35}{16\cdot35}=\dfrac{-175}{560}\)
\(\dfrac{3}{-20}=\dfrac{-3}{20}=\dfrac{-3\cdot28}{20\cdot28}=\dfrac{-84}{560}\)
\(\dfrac{6}{28}=\dfrac{6\cdot20}{28\cdot20}=\dfrac{120}{560}\)
4: \(\dfrac{1}{42}=\dfrac{1\cdot10}{42\cdot10}=\dfrac{10}{420}\)
\(\dfrac{-7}{30}=\dfrac{-7\cdot14}{30\cdot14}=\dfrac{-98}{420}\)
\(-\dfrac{9}{12}=\dfrac{-9\cdot35}{12\cdot35}=\dfrac{-315}{420}\)
5: \(\dfrac{9}{-14}=\dfrac{-9}{14}=\dfrac{-9\cdot21}{14\cdot21}=\dfrac{-189}{294}\)
\(\dfrac{5}{42}=\dfrac{5\cdot7}{42\cdot7}=\dfrac{35}{294}\)
\(\dfrac{-3}{49}=\dfrac{-3\cdot6}{49\cdot6}=\dfrac{-18}{294}\)
6: \(\dfrac{-13}{45}=\dfrac{-13\cdot8}{45\cdot8}=\dfrac{-104}{360}\)
\(\dfrac{7}{15}=\dfrac{7\cdot24}{15\cdot24}=\dfrac{168}{360}\)
\(\dfrac{-3}{40}=\dfrac{-3\cdot9}{40\cdot9}=-\dfrac{270}{360}\)
7: \(\dfrac{2}{5}=\dfrac{2\cdot63}{5\cdot63}=\dfrac{126}{315}\)
\(\dfrac{13}{45}=\dfrac{13\cdot7}{45\cdot7}=\dfrac{91}{315}\)
\(\dfrac{-12}{35}=\dfrac{-12\cdot9}{35\cdot9}=\dfrac{-108}{315}\)
8: \(\dfrac{4}{17}=\dfrac{4\cdot6}{17\cdot6}=\dfrac{24}{102}\)
\(\dfrac{8}{51}=\dfrac{8\cdot2}{51\cdot2}=\dfrac{16}{102}\)
\(\dfrac{3}{34}=\dfrac{3\cdot3}{34\cdot3}=\dfrac{9}{102}\)
9: \(\dfrac{9}{13}=\dfrac{9\cdot30}{13\cdot30}=\dfrac{270}{390}\)
\(\dfrac{-6}{65}=\dfrac{-6\cdot6}{65\cdot6}=\dfrac{-36}{360}\)
\(\dfrac{-7}{39}=\dfrac{-7\cdot10}{39\cdot10}=-\dfrac{70}{390}\)
