Resposta :
Olá!
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[tex] \\ { \large \displaystyle \sf {a) \: \frac{20}{100} = \frac{20 \div 20}{100 \div 20} = \boxed{ \pink{ \: \: \frac{1}{5} \: \: }}}} \\ \\ \\ [/tex]
[tex] { \large \displaystyle \sf {b) \: \frac{5}{25} = \frac{5 \div 5}{25 \div 5} = \boxed{ \pink{ \: \: \frac{1}{5} \: \: }}}} \\ \\ \\ [/tex]
[tex] { \large \displaystyle \sf {c) \: \frac{11}{16} = }}[/tex]