[tex]zad.a)~~9\dfrac{4}{5} -3\dfrac{3}{4} =9\dfrac{16}{20} -3\dfrac{15}{20} =6\dfrac{1}{20} \\\\zad.b)~~6\dfrac{1}{3} -2\dfrac{5}{6} =6\dfrac{2}{6} -2\dfrac{5}{6} =5\dfrac{8}{6} -2\dfrac{5}{6}=3\dfrac{3}{6} =3\dfrac{1}{2}\\\\zad.c)~~9\dfrac{6}{7} -1\dfrac{1}{11} =9\dfrac{66}{77} -1\dfrac{7}{77}=8\dfrac{59}{77}[/tex]
