Ответ:

а)

Аввал ҳар як қавсро ҳисоб мекунем:

\(5\frac{3}{7}-3\frac{2}{5}=\frac{38}{7}-\frac{17}{5}=\frac{190-119}{35}=\frac{71}{35}=2\frac{1}{35}\).

\(3-1\frac{17}{35}=\frac{105}{35}-\frac{52}{35}=\frac{53}{35}=1\frac{18}{35}\).

\(4\frac{12}{15}-3\frac{19}{105}=4\frac{84}{105}-3\frac{19}{105}=1\frac{65}{105}=1\frac{13}{21}\).

Акнун натиҷаҳоро ҷамъу тарҳ мекунем:

\(\frac{71}{35}+\frac{53}{35}-\frac{65}{105}=\frac{213+159-65}{105}=\frac{307}{105}=2\frac{97}{105}\).

б)

Ҳар як қавсро ҳисоб мекунем:

\(7\frac{7}{9}-5\frac{1}{3}=\frac{70}{9}-\frac{16}{3}=\frac{70-48}{9}=\frac{22}{9}\).

\(2-1\frac{5}{6}=\frac{12}{6}-\frac{11}{6}=\frac{1}{6}\).

\(9\frac{19}{36}-3\frac{11}{12}=9\frac{19}{36}-3\frac{33}{36}=5\frac{22}{36}=5\frac{11}{18}\).

Натиҷаҳоро бо махраҷи умумии 18 ҷамъ мекунем:

\(\frac{22}{9}-\frac{1}{6}+5\frac{11}{18}=\frac{44}{18}-\frac{3}{18}+\frac{101}{18}=\frac{142}{18}=\frac{71}{9}=7\frac{8}{9}\).

Ҷавоб: а) \(2\frac{97}{105}\); б) \(7\frac{8}{9}\).