[tex]a) \frac{9}{10} = \frac{18}{20} = \frac{27}{30} = \frac{36}{40} = \frac{45}{50} = \frac{54}{60} = \frac{63}{70} = \frac{72}{80} = \frac{81}{90} = \frac{90}{100} \\\\b) \frac{7}{12} = \frac{14}{24} = \frac{21}{36} = \frac{28}{48} = \frac{35}{60} = \frac{42}{72} = \frac{49}{84} = \frac{56}{96} \\\\c) \frac{10}{25} = \frac{20}{50} = \frac{30}{75} = \frac{40}{100}\\\\d) \frac{12}{36} = \frac{24}{72}[/tex]
