1. Выполните действие: a) 3,8-5,7; в) 3,9-8,4; 6) -8,4+3,7; г) -2,9+7,3; e) -1-2금

1. Выполните действие:

1. а) 3,8 - 5,7 = - (5,7 - 3,8) = - 1,9
2. б) -8,4 + 3,7 = - (8,4 - 3,7) = - 4,7
3. в) 3,9 - 8,4 = - (8,4 - 3,9) = - 4,5
4. г) -2,9 + 7,3 = 7,3 - 2,9 = 4,4
5. д) -\(\frac{2}{9}\) + \(\frac{5}{6}\) = -\(\frac{2\cdot2}{9\cdot2}\) + \(\frac{5\cdot3}{6\cdot3}\) = -\(\frac{4}{18}\) + \(\frac{15}{18}\) = \(\frac{15-4}{18}\) = \(\frac{11}{18}\)
6. е) -1\(\frac{3}{4}\) - 2\(\frac{1}{12}\) = -\(\frac{1\cdot4+3}{4}\) - \(\frac{2\cdot12+1}{12}\) = -\(\frac{7}{4}\) - \(\frac{25}{12}\) = -\(\frac{7\cdot3}{4\cdot3}\) - \(\frac{25}{12}\) = -\(\frac{21}{12}\) - \(\frac{25}{12}\) = -\(\frac{21+25}{12}\) = -\(\frac{46}{12}\) = -\(\frac{23}{6}\) = -3\(\frac{5}{6}\)