4.257 Вычислите: 3 5 a)-4-(-2); B) -2-+): 2 6) 5-6 7 5 ; 14 г) - 0,9; 17 30 д) -(-0,6); e) -5,1-3; 1 7 ж) 12,5 – 72; 3) -3-(-4,2). 4'

4.257 Вычислите:

a) \[-4\frac{1}{3} - (-2\frac{7}{9}) = -4\frac{1}{3} + 2\frac{7}{9} = -4\frac{3}{9} + 2\frac{7}{9} = -3\frac{12}{9} + 2\frac{7}{9} = -1\frac{5}{9}\]

б) \[5\frac{2}{7} - 6\frac{5}{14} = 5\frac{4}{14} - 6\frac{5}{14} = -1\frac{1}{14}\]

в) \[-2\frac{3}{16} + \frac{5}{8} = -2\frac{3}{16} + \frac{10}{16} = -2 + \frac{10}{16} - \frac{3}{16} = -2 + \frac{7}{16} = -1\frac{9}{16}\]

г) \(\frac{3}{5} - 0,9 = \frac{3}{5} - \frac{9}{10} = \frac{6}{10} - \frac{9}{10} = -\frac{3}{10} = -0,3\)

д) \(\frac{17}{30} - (-0,6) = \frac{17}{30} + 0,6 = \frac{17}{30} + \frac{6}{10} = \frac{17}{30} + \frac{18}{30} = \frac{35}{30} = \frac{7}{6} = 1\frac{1}{6}\)

е) \[-5,1 - 3\frac{1}{7} = -5\frac{1}{10} - 3\frac{1}{7} = -5\frac{7}{70} - 3\frac{10}{70} = -8\frac{17}{70}\]

ж) \(12,5 - 7\frac{3}{4} = 12\frac{1}{2} - 7\frac{3}{4} = 12\frac{2}{4} - 7\frac{3}{4} = 11\frac{6}{4} - 7\frac{3}{4} = 4\frac{3}{4}\)

з) \[-3\frac{1}{7} - (-4,2) = -3\frac{1}{7} + 4,2 = -3\frac{1}{7} + 4\frac{2}{10} = -3\frac{1}{7} + 4\frac{1}{5} = -3\frac{5}{35} + 4\frac{7}{35} = 1\frac{2}{35}\]