a)
4\frac{2}{3}-1\frac{3}{4}=4\frac{8}{12}-1\frac{9}{12}=3\frac{20}{12}-1\frac{9}{12}=2\frac{11}{12}
2\frac{11}{12}+1\frac{9}{12}=3\frac{20}{12}=4\frac{8}{12}=4\frac{2}{3}
b)
5\frac{5}{6}-3\frac{7}{8}=5\frac{20}{24}-3\frac{21}{24}=4\frac{44}{24}-3\frac{21}{24}=1\frac{23}{24}
c)
5\frac{12}{25}-2\frac{17}{20}=5,48-2,85=2,63
d)
6\frac{11}{12}-4\frac{5}{8}=6\frac{22}{24}-4\frac{15}{24}=2\frac{7}{24}
e)
3\frac{5}{8}-1\frac{8}{15}=3\frac{75}{120}-1\frac{64}{120}=2\frac{11}{120}
f)
7\frac{11}{18}-5\frac{11}{12}=7\frac{22}{36}-5\frac{33}{36}=6\frac{58}{36}-5\frac{33}{36}=1\frac{25}{36}
g)
9\frac{5}{12}-4\frac{5}{6}=9\frac{5}{12}-4\frac{10}{12}=8\frac{17}{12}-4\frac{10}{12}=4\frac{7}{12}
h)
7\frac{1}{7}-4\frac{5}{6}=7\frac{6}{42}-4\frac{35}{42}=6\frac{48}{42}-4\frac{35}{42}=2\frac{13}{42}
i)
65\frac{3}{8}-48\frac{4}{5}=65\frac{15}{40}-48\frac{32}{40}=64\frac{55}{40}-48\frac{32}{40}=16\frac{23}{40}
j)
42\frac{4}{15}-16\frac{8}{9}=42\frac{36}{45}-16\frac{40}{45}=41\frac{81}{45}-16\frac{40}{45}=25\frac{41}{45}
k)
51\frac{3}{22}-19\frac{5}{33}=51\frac{9}{66}-19\frac{10}{66}=50\frac{75}{66}-19\frac{10}{66}=31\frac{65}{66}
l)
46\frac{5}{6}-27\frac{19}{21}=46\frac{35}{42}-27\frac{38}{42}=45\frac{77}{42}-27\frac{38}{42}=18\frac{39}{42}=18\frac{13}{14}