Реши примеры по теме сложения и вычитания обыкновенных дробей: 1) 17 7/18 - 2 2/9

Конечно, давай решим эти примеры вместе! 1) $17 \frac{7}{18} - 2 \frac{2}{9} = 17 \frac{7}{18} - 2 \frac{4}{18} = (17-2) + (\frac{7}{18} - \frac{4}{18}) = 15 + \frac{3}{18} = 15 \frac{1}{6}$ 2) $11 \frac{5}{18} - 10 \frac{31}{54} = 11 \frac{15}{54} - 10 \frac{31}{54} = (11-10) + (\frac{15}{54} - \frac{31}{54}) = 1 - \frac{16}{54} = 1 - \frac{8}{27} = \frac{27}{27} - \frac{8}{27} = \frac{19}{27}$ 3) $3 \frac{13}{15} + 2 \frac{13}{16} = 3 \frac{208}{240} + 2 \frac{195}{240} = (3+2) + (\frac{208}{240} + \frac{195}{240}) = 5 + \frac{403}{240} = 5 + 1 \frac{163}{240} = 6 \frac{163}{240}$ 4) $7 \frac{11}{13} + 21 \frac{17}{30} = 7 \frac{330}{390} + 21 \frac{221}{390} = (7+21) + (\frac{330}{390} + \frac{221}{390}) = 28 + \frac{551}{390} = 28 + 1 \frac{161}{390} = 29 \frac{161}{390}$ 5) $5 - 2 \frac{1}{6} = 4 \frac{6}{6} - 2 \frac{1}{6} = (4-2) + (\frac{6}{6} - \frac{1}{6}) = 2 + \frac{5}{6} = 2 \frac{5}{6}$ 6) $10 - \frac{10}{11} = 9 \frac{11}{11} - \frac{10}{11} = 9 \frac{1}{11}$ 7) $25 \frac{5}{8} + 18 \frac{3}{4} = 25 \frac{5}{8} + 18 \frac{6}{8} = (25+18) + (\frac{5}{8} + \frac{6}{8}) = 43 + \frac{11}{8} = 43 + 1 \frac{3}{8} = 44 \frac{3}{8}$ 8) $2 \frac{1}{2} - \frac{17}{24} = 2 \frac{12}{24} - \frac{17}{24} = 1 \frac{36}{24} - \frac{17}{24} = 1 \frac{19}{24}$ 9) $4 \frac{4}{12} + 13 \frac{4}{5} - 5 \frac{5}{6} + 7 \frac{9}{11} = 4 \frac{220}{660} + 13 \frac{528}{660} - 5 \frac{550}{660} + 7 \frac{540}{660} = (4+13-5+7) + (\frac{220}{660} + \frac{528}{660} - \frac{550}{660} + \frac{540}{660}) = 19 + \frac{738}{660} = 19 + 1 \frac{78}{660} = 20 \frac{13}{110}$ Надеюсь, теперь тебе всё понятно!