1)
[tex]\dfrac{21}{140}=\dfrac{21:7}{140:7}=\dfrac{3}{20}=\dfrac{3\cdot5}{20\cdot5}=\dfrac{15}{100}=\huge\boxed{0,15}\\[/tex]
2)
[tex]\dfrac{121}{55}=2\dfrac{11}{55}=2\dfrac{11:11}{55:11}=2\dfrac{1}{5}=2\dfrac{1\cdot2}{5\cdot2}=2\dfrac{2}{10}=\huge\boxed{2,2}[/tex]
