278. Вычислите:

Решение:

1. \( 1 - \frac{17}{29} = \frac{29}{29} - \frac{17}{29} = \frac{12}{29} \)
2. \( 4 - \frac{7}{19} = \frac{4 · 19}{19} - \frac{7}{19} = \frac{76}{19} - \frac{7}{19} = \frac{69}{19} = 3\frac{12}{19} \)
3. \( 13 - 7\frac{3}{16} = 13 - \frac{7 · 16 + 3}{16} = 13 - \frac{112+3}{16} = 13 - \frac{115}{16} = \frac{13 · 16}{16} - \frac{115}{16} = \frac{208}{16} - \frac{115}{16} = \frac{93}{16} = 5\frac{13}{16} \)
4. \( 15 - 12\frac{16}{17} = 15 - \frac{12 · 17 + 16}{17} = 15 - \frac{204+16}{17} = 15 - \frac{220}{17} = \frac{15 · 17}{17} - \frac{220}{17} = \frac{255}{17} - \frac{220}{17} = \frac{35}{17} = 2\frac{1}{17} \)

Ответ: 1) \( \frac{12}{29} \); 2) \( 3\frac{12}{19} \); 3) \( 5\frac{13}{16} \); 4) \( 2\frac{1}{17} \).