7) 8/17 : (12/17 + 2 7/11)

7) \(\frac{8}{17} : (\frac{12}{17} + 2\frac{7}{11}) = \frac{8}{17} : (\frac{12}{17} + \frac{29}{11}) = \frac{8}{17} : (\frac{132}{187} + \frac{493}{187}) = \frac{8}{17} : \frac{625}{187} = \frac{8}{17} \cdot \frac{187}{625} = \frac{8 \cdot 11}{625} = \frac{88}{625}\)
Ответ: 88/625