3,75*\frac{2}{3}=3\frac{3}{4}*\frac{2}{3}=\frac{15}{4}*\frac{2}{3}=\frac{5}{2}=2,5
5\frac{1}{2}-0,7=5,5-0,7=4,8
5,125+1\frac{3}{4}=5,125+1,75=6,875=6\frac{7}{8}
8,45-3\frac{3}{4}=8,45-3,75=4,7
1\frac{1}{4}*4,2=1.25*4,2=5,25
1\frac{2}{3}:4,5=\frac{5}{3}:4\frac{1}{2}=\frac{5}{3}:\frac{9}{2}=\frac{5}{3}*\frac{2}{9}=\frac{10}{27}
4,12:3\frac{2}{3}=\frac{412}{100}*\frac{3}{11}=\frac{103}{25}*\frac{3}{11}=\frac{309}{275}=1\frac{34}{275}
6,3+4\frac{5}{7}+\frac{2}{5}=6\frac{3}{10}+4\frac{5}{7}+\frac{2}{5}=6\frac{21}{70}+4\frac{50}{70}+\frac{28}{70}=10\frac{129}{70}=11\frac{59}{70}
12,75-0,28+0,64=13,11
9,72-3\frac{3}{5}*1\frac{2}{3}=9,72-\frac{18*5}{5*3}=9,72-6=3,72
5,08-2,08:\frac{13}{25}=5,08-2,08:0,52=5,08-4=1,08
5,4:(5\frac{3}{7}-3\frac{4}{5})=5\frac{4}{10}:(5\frac{15}{35}-3\frac{28}{35})=\frac{54}{10}:1\frac{22}{35}=\frac{27}{5}*\frac{35}{57}=\frac{63}{19}=3\frac{6}{19}
0,1^2+0,2^3=0,01+0,008=0,018
(\frac{2}{3}-\frac{3}{10})^2=(\frac{20}{30}-\frac{9}{30})^2=(\frac{11}{30})^2=\frac{121}{900}