$\dfrac{4}{20}$

$\dfrac{7}{21}$

$\dfrac{8}{80}$

$\dfrac{55}{220}$

$\dfrac{16}{64}$

$\dfrac{12}{44}$

$\dfrac{24}{66}$

$\dfrac{18}{30}=\dfrac{3}{}$

$\dfrac{16}{52}=\dfrac{}{13}$

$\dfrac{15}{35}=\dfrac{}{7}$

$\dfrac{27}{45}=\dfrac{}{5}$

$\dfrac{56}{64}=\dfrac{7}{}$

$\dfrac{192}{256}\hphantom{11}(64)$

$\dfrac{112}{144}\hphantom{11}(16)$

$\dfrac{96}{120} \hphantom{11}(24)$

$\dfrac{3}{4}; \dfrac{8}{16}; \dfrac{3}{12}$

$\dfrac{4}{6}; \dfrac{4}{24}; \dfrac{12}{36}$

$\dfrac{7}{9};\dfrac{9}{7};\dfrac{10}{13}$

$\dfrac{12}{42}=\dfrac{4}{14}$

$\dfrac{14}{63}=\dfrac{2}{9}$

$\dfrac6{24}\;\;[6]$

$\dfrac{27}{60}\;\;[3]$

$\dfrac36$

$\dfrac{50}{20}$

$\dfrac{75\;\cdot\;119\;\cdot\;54}{45\;\cdot\;144\;\cdot\;51}$

$\dfrac{42}{96}$

$\frac12$

$\frac{13}7$

$\frac{60}{12}$

$\dfrac{2}{4}=\dfrac{\ \ \ \ }{6}$

$\dfrac{12}{16}=\dfrac{\ \ \ \ \ \ \ }{12}$

$\dfrac{8}{7}=\dfrac{\ \ \ \ }{21}$

$\dfrac{4}{12}=\dfrac{\ \ \ \ }{60}$

$\dfrac{6}{3}=\dfrac{\ \ \ \ }{24}$

$\frac{4}{7}\ \left[3\right]$ =

$\frac{12}{25}\ \left[6\right]$

$\frac{7}{18}\ \left[18\right]$

$\frac{2}{15}\ \left[10\right]$

$\frac{31}{32}\ \left[100\right]$

$\frac{21}{64}\ \left[29\right]$

$\frac47\left[28\right]$

$\frac2{15}\left[60\right]$

$\frac7{18}\left[108\right]$

$\frac7{15}\left[225\right]$

$\frac{31}{32}\left[512\right]$

$\frac{15}{17}\left[1870\right]$

$\frac{4}{7}\ \left[36\right]$

$\frac{12}{25}\ \left[600\right]$

$\frac{7}{9}\ \left[84\right]$

$\frac{17}{25}\ \left[187\right]$

$\frac{31}{32}\ \left[248\right]$

$\frac{5}{7}\ \left[1860\right]$

$\frac{3}{18}$

$\frac{2}{80}$

$\frac{7}{49}$

$\frac{12}{36}$

$\frac{4}{32}$