217. Выполните действия в соответствии с их порядком: а) (5 5/7 · 3/8 − 5 1/4 : 7) : 3 + 3 3/28 − 1/2; б) (6 1/4 · 2 2/15 − 5 1/3 : 8/9) : 11 + 1 3/4 − 3/4; в) (2 1/2 + 3 1/3) : (2 1/2 − 1 1/3) : ((4 3/5 + 2 1/3) : (4 3/5 − 2 1/3)); г) 6 3/4 : 3 + 27/40 · ((6 7/12 − 3 17/36) · 2 1/2 − 4 1/3 · 13/20) − 1 1/4.

1. \(\left(5\frac57\cdot\frac38-5\frac14:7\right):3+3\frac3{28}-\frac12\)

   \(=\left(\frac{40}{7}\cdot\frac38-\frac{21}{4}:7\right):3+\frac{87}{28}-\frac12\)

   \(=\left(\frac{15}{7}-\frac34\right):3+\frac{73}{28}=\frac{23}{28}:3+\frac{73}{28}=\frac{23}{84}+\frac{219}{84}=\frac{121}{42}.\)

2. \(\left(6\frac14\cdot2\frac2{15}-5\frac13:\frac89\right):11+1\frac34-\frac34\)

   \(=\left(\frac{25}{4}\cdot\frac{32}{15}-\frac{16}{3}\cdot\frac98\right):11+1\)

   \(=\left(\frac{40}{3}-6\right):11+1=\frac6{11}+1=\frac{17}{11}.\)

3. \((2\frac12+3\frac13):(2\frac12-1\frac13):((4\frac35+2\frac13):(4\frac35-2\frac13))\)

   \(=\frac{35/6}{7/6}:\frac{104/15}{34/15}=5:\frac{52}{17}=\frac{85}{52}.\)

4. \(6\frac34:3+\frac{27}{40}\left((6\frac7{12}-3\frac{17}{36})\cdot2\frac12-4\frac13\cdot\frac{13}{20}\right)-1\frac14\)

   \(=\frac94+\frac{27}{40}\left(\frac{61}{18}\cdot\frac52-\frac{13}{3}\cdot\frac{13}{20}\right)-\frac54\)

   \(=1+\frac{27}{40}\left(\frac{305}{36}-\frac{169}{60}\right)=1+\frac{27}{40}\cdot\frac{113}{18}=\frac{679}{160}.\)

Ответ: а) 121/42; б) 17/11; в) 85/52; г) 679/160.