Помогите пожалуйста решить 1 7/20:2,75+1,35:2 3/4+(0,49:2 1/3):(4,89-1 17/19)

Решите задачу:

$1 \frac{7}{20} : 2,75 + 1,35 : 2 \frac{3}{4} + (0,49 : 2 \frac{1}{3} ) :(4,89 - 1 \frac{17}{19} ) =1\frac{774}{14905} \\ \\$

$1) 0,49 : 2 \frac{1}{3} = \frac{49}{100} * \frac{3}{7} = \frac{7*3}{100*1} = \frac{21}{100} =0,21 \\ \\ 2) 4,89 - 1 \frac{17}{19} = \frac{489}{100} - \frac{36}{19} = \frac{9291-3600}{1900} = \frac{5691}{1900} = 2 \frac{1891}{1900} \\ \\ 3) 1 \frac{7}{20} : 2,75 = \frac{27}{20} * \frac{100}{275} = \frac{27}{20} * \frac{4}{11} = \frac{27*1}{5*11} = \frac{27}{55} \\$
$4) 1,35 : 2 \frac{3}{4} = \frac{135}{100} * \frac{4}{11} = \frac{27}{20} * \frac{4}{11} = \frac{27*1}{5*11} = \frac{27}{55} \\ \\$

$5)0,21 : 2 \frac{1891}{1900}= 0,21: \frac{5691}{1900}= \frac{21}{100} * \frac{1900}{5691} = \frac{1*19}{1*271} = \frac{19}{271} \\ \\ 6) \frac{27}{55}+ \frac{27}{55} = \frac{27+27}{55} = \frac{54}{55} \\ \\ 7) \frac{54}{55} + \frac{19}{271} = \frac{54*271+19*55}{14905} = \frac{14634+1045}{14905} = \frac{15679}{14905}= 1 \frac{774}{14905} \\$