Решение:
- а) \( \frac{8}{11} - z = 3\frac{9}{11} \)
\( z = \frac{8}{11} - 3\frac{9}{11} \)
\( z = \frac{8}{11} - \frac{3 \cdot 11 + 9}{11} = \frac{8}{11} - \frac{42}{11} = \frac{8 - 42}{11} = -\frac{34}{11} = -3\frac{1}{11} \) - б) \( y - 4\frac{3}{5} = 2\frac{4}{5} \)
\( y = 2\frac{4}{5} + 4\frac{3}{5} \)
\( y = (2+4) + (\frac{4}{5} + \frac{3}{5}) = 6 + \frac{7}{5} = 6 + 1\frac{2}{5} = 7\frac{2}{5} \) - в) \( 8\frac{16}{27} - (x - 2\frac{17}{27}) = 5\frac{8}{27} \)
\( x - 2\frac{17}{27} = 8\frac{16}{27} - 5\frac{8}{27} \)
\( x - 2\frac{17}{27} = (8-5) + (\frac{16}{27} - \frac{8}{27}) = 3 + \frac{8}{27} = 3\frac{8}{27} \)
\( x = 3\frac{8}{27} + 2\frac{17}{27} \)
\( x = (3+2) + (\frac{8}{27} + \frac{17}{27}) = 5 + \frac{25}{27} = 5\frac{25}{27} \)
Ответ: а) \( z = -3\frac{1}{11} \); б) \( y = 7\frac{2}{5} \); в) \( x = 5\frac{25}{27} \).