51. Вычислите: 1) \(1 - \frac{5}{27}\); 2) \(9 - \frac{17}{23}\); 3) \(6 - 1\frac{2}{9}\); 4) \(7 - 3\frac{12}{35}\);

1) \(1 - \frac{5}{27} = \frac{27}{27} - \frac{5}{27} = \frac{27-5}{27} = \frac{22}{27}\)

2) \(9 - \frac{17}{23} = \frac{9 \cdot 23}{23} - \frac{17}{23} = \frac{207}{23} - \frac{17}{23} = \frac{207-17}{23} = \frac{190}{23} = 8\frac{6}{23}\)

3) \(6 - 1\frac{2}{9} = 6 - \frac{11}{9} = \frac{6 \cdot 9}{9} - \frac{11}{9} = \frac{54}{9} - \frac{11}{9} = \frac{54-11}{9} = \frac{43}{9} = 4\frac{7}{9}\)

4) \(7 - 3\frac{12}{35} = 7 - \frac{3 \cdot 35 + 12}{35} = 7 - \frac{105 + 12}{35} = 7 - \frac{117}{35} = \frac{7 \cdot 35}{35} - \frac{117}{35} = \frac{245}{35} - \frac{117}{35} = \frac{245-117}{35} = \frac{128}{35} = 3\frac{23}{35}\)