Question

помогите по матем эти дроби​

Answer 1

$\tt\displaystyle 1) \, \, \frac{1}{4} - (1 - \frac{11}{12}) = \frac{1}{4} - (\frac{12}{12} - \frac{11}{12}) = \frac{1}{4} - \frac{1}{12} = \frac{3-1}{12} = \frac{2}{12} = \frac{1}{6} \\\\ 2) \, \, 2 - (\frac{13}{33} - \frac{5}{22}) = 2 - (\frac{13\cdot 2-5\cdot 3}{66}) = 2 - (\frac{26-15}{66}) = 2 - \frac{11}{66} = 2 - \frac{1}{6} = \\\\ 1 \frac{6}{6} - \frac{1}{6} = 1 \frac{5}{6} \\\\ 3) \, \, 6 \frac{3}{16} - (2 \frac{3}{5} + 3 \frac{5}{12}) = 6 \frac{3}{16} - ( (2+3) + \frac{3\cdot 12+5\cdot 5}{60}) = 6 \frac{3}{16} - 5 \frac{36 + 25}{60} = \\\\ (6-6) + (\frac{3}{16} - \frac{1}{60}) = \frac{3\cdot 15-1\cdot 4}{240} = \frac{41}{240} \\\\ 4) \, \, 8 \frac{1}{12} - 3 \frac{4}{15} - 1 \frac{7}{30} = (8-3-1) + (\frac{1}{12} - \frac{4}{15} - \frac{7}{30}) = 4 + (\frac{1\cdot 5-4\cdot 4-7\cdot 2}{60}) = \\\\ 4 + \frac{5-16-14}{60} = 3 + \frac{65-16-14}{60} = 3 \frac{35}{60} = 3 \frac{7}{12}$