ГДЗ Математика 6 клас Істер — Вправа 1101

1) $\frac{4}{19} + \left(-\frac{5}{19}\right) + \frac{7}{19} + \left(-\frac{13}{19}\right) = \left(\frac{4}{19} + \frac{7}{19}\right) + \left(-\frac{5}{19} - \frac{13}{19}\right) =$

$= \frac{11}{19} + \left(-\frac{18}{19}\right) = -\frac{7}{19};$

2) $1\frac{2}{3} + \left(-\frac{8}{17}\right) + 5\frac{1}{3} + \left(-\frac{9}{17}\right) = \left(1\frac{2}{3} + 5\frac{1}{3}\right) + \left(-\frac{8}{17} - \frac{9}{17}\right) =$

$= 7 + (-1) = 6;$

3) $-5\frac{1}{7} + 4\frac{4}{7} + 2\frac{6}{7} + \left(-1\frac{2}{7}\right) = \left(-5\frac{1}{7} - 1\frac{2}{7}\right) + \left(4\frac{4}{7} + 2\frac{6}{7}\right) =$

$= -6\frac{3}{7} + 7\frac{3}{7} = 1;$

4) $9\frac{1}{11} + 5\frac{7}{13} + \left(-8\frac{3}{11}\right) + \left(-5\frac{7}{13}\right) = \left(9\frac{1}{11} - 8\frac{3}{11}\right) + \left(5\frac{7}{13} - 5\frac{7}{13}\right) =$

$= \frac{9}{11} + 0 = \frac{9}{11}.$