Помогите я на уроке(((

Решите задачу:

$2)\frac{2\frac19:1\frac16+3,5}{4\frac27:2\frac17-0,9}=\frac{\frac{19}9:\frac76+3,5}{\frac{30}7:\frac{15}7-0,9}=\frac{\frac{19}9\cdot\frac67+3,5}{\frac{30}7\cdot\frac7{15}-0,9}=\frac{\frac{19}3\cdot\frac27+3\frac12}{2-0,9}=\frac{\frac{38}{21}+\frac72}{1,1}=\\=\frac{\frac{76}{42}+\frac{147}{42}}{1\frac1{10}}=\frac{\frac{223}{42}}{\frac{11}{10}}=\frac{223\cdot10}{42\cdot11}=\frac{223\cdot5}{21\cdot11}=\frac{1115}{231}=4\frac{191}{231}$

$3)\;\frac{3,9:1,3-1,32}{0,51:1,7+3,06}=\frac{3-1,32}{0,3+3,06}=\frac{1,68}{3,36}=\frac12=0,5\\\\2)\;\frac{4,5:0,15\cdot0,5}{8,5\cdot\frac3{17}:0,3}=\frac{30\cdot0,5}{8\frac12\cdot\frac3{17}:\frac3{10}}=\frac{15}{\frac{17}2\cdot\frac3{17}\cdot\frac{10}3}=\frac{15}5=3\\\\3)\;\frac{0,99\cdot0,2\cdot10,4}{0,22\cdot0,9\cdot1,3}=\frac{9\cdot0,2\cdot8}{2\cdot0,9\cdot1}=\frac{9\cdot0,2\cdot4}{0,9}=10\cdot0,2\cdot4=2\cdot4=8$

Помогите я ** уроке(((