Помогите решить пример и уравнение:

Решите задачу:

$12 \frac{5}{33}-4 \frac{19}{21} =12 \frac{35}{231} -4 \frac{209}{231} =11 \frac{266}{231} -4 \frac{209}{231} =7 \frac{57}{231} \\ 15 \frac{9}{77} -7 \frac{57}{231} =15 \frac{27}{231} -7 \frac{57}{231} =14 \frac{258}{231} -7 \frac{57}{231} =7 \frac{201}{231} =7 \frac{67}{77} \\ \\ \\ x=7 \frac{41}{72} +5 \frac{13}{24} \\ x=7 \frac{41}{72} +5 \frac{39}{72} \\ x=12 \frac{80}{72} \\ x=13 \frac{8}{72} =13 \frac{1}{9}$