номер 2.205

Полное решение № 2.205:

а) \[ 4\frac{2}{9}+3\frac{5}{18} =4\frac{4}{18}+3\frac{5}{18} =7\frac{9}{18} =7\frac{1}{2} \]

б) \[ 3\frac{5}{12}+4\frac{7}{9} =3\frac{15}{36}+4\frac{28}{36} =7\frac{43}{36} =8\frac{7}{36} \]

в) \[ 7\frac{11}{12}+1\frac{3}{8} =7\frac{22}{24}+1\frac{9}{24} =8\frac{31}{24} =9\frac{7}{24} \]

г) \[ 4\frac{3}{8}+2\frac{4}{11} =4\frac{33}{88}+2\frac{32}{88} =6\frac{65}{88} \]

д) \[ 6\frac{5}{11}+5=11\frac{5}{11} \]

е) \[ 7\frac{3}{7}+\frac{5}{21} =7\frac{9}{21}+\frac{5}{21} =7\frac{14}{21} =7\frac{2}{3} \]

ж) \[ 6+4\frac{2}{7}=10\frac{2}{7} \]

з) \[ \frac{3}{7}+3\frac{4}{5} =3+\frac{15}{35}+\frac{28}{35} =3\frac{43}{35} =4\frac{8}{35} \]

Ответы:
а) \(7\frac{1}{2}\); б) \(8\frac{7}{36}\); в) \(9\frac{7}{24}\); г) \(6\frac{65}{88}\);
д) \(11\frac{5}{11}\); е) \(7\frac{2}{3}\); ж) \(10\frac{2}{7}\); з) \(4\frac{8}{35}\).

Полное решение № 2.207:

а) \[ 5\frac{7}{15}-\frac{3}{20} =5+\frac{28}{60}-\frac{9}{60} =5\frac{19}{60} \]

б) \[ 4\frac{7}{12}-\frac{2}{9} =4+\frac{21}{36}-\frac{8}{36} =4\frac{13}{36} \]

в) \[ 6\frac{5}{7}-\frac{3}{14} =6+\frac{10}{14}-\frac{3}{14} =6\frac{7}{14} =6\frac{1}{2} \]

г) \[ 7\frac{5}{7}-4\frac{2}{3} =(7-4)+\left(\frac{15}{21}-\frac{14}{21}\right) =3\frac{1}{21} \]

д) \[ 3\frac{2}{3}-3\frac{4}{11} =\frac{22}{33}-\frac{12}{33} =\frac{10}{33} \]

е) \[ 7\frac{5}{12}-3\frac{2}{9} =(7-3)+\left(\frac{15}{36}-\frac{8}{36}\right) =4\frac{7}{36} \]

Ответы:
а) \(5\frac{19}{60}\); б) \(4\frac{13}{36}\); в) \(6\frac{1}{2}\);
г) \(3\frac{1}{21}\); д) \(\frac{10}{33}\); е) \(4\frac{7}{36}\).