Помогите пожалуйста даю 20 баллов

Решите задачу:

$1) \ 6:\frac{3}{5}=6\cdot\frac{5}{3}=2\cdot5=10, \\ 2) \ 1\frac{1}{6}\cdot\frac{6}{7}=\frac{1\cdot6+1}{6}\cdot\frac{6}{7}=\frac{7}{6}\cdot\frac{6}{7}=1, \\ 3) \ 10-1=9, \\ 4) \ 4\frac{1}{5}\cdot\frac{10}{11}=\frac{4\cdot5+1}{5}\cdot\frac{10}{11}=\frac{21}{5}\cdot\frac{10}{11}=21\cdot\frac{2}{11}=\frac{42}{11}=3\frac{9}{11}, \\ 5) \ 3\frac{9}{11}+5\frac{2}{11}=8\frac{11}{11}=9, \\ 6) \ \frac{9}{9}=1;$
$7) \ \frac{3}{20}+\frac{1}{2}=\frac{3}{20}+\frac{10}{20}=\frac{13}{20}, \\ 8) \ \frac{13}{20}-\frac{1}{15}=\frac{39}{60}-\frac{4}{60}=\frac{35}{60}=\frac{7}{12}, \\ 9) \ \frac{7}{12}\cdot\frac{12}{49}=1\cdot\frac{1}{7}=\frac{1}{7}, \\ 10) \ \frac{1}{5}+\frac{1}{7}=\frac{7}{35}+\frac{5}{35}=\frac{12}{35}, \\ 11) \ \frac{\frac{1}{7}}{\frac{12}{35}}=\frac{1\cdot35}{7\cdot12}=\frac{5}{12}; \\ 12) \ 1-\frac{5}{12}=\frac{12}{12}-\frac{5}{12}=\frac{7}{12};$
$13) \ \frac{7}{12}\cdot2\frac{1}{3}=\frac{7}{12}\cdot\frac{7}{3}=\frac{49}{36}, \\ 14) \ 3\frac{1}{4}-\frac{49}{36}=\frac{13}{4}-\frac{49}{36}=\frac{117}{36}-\frac{49}{36}=\frac{68}{36}=\frac{17}{9}=1\frac{8}{9}.$