181. Найдите значение выражения:

Решение:

1. \( -36 + 79 - 42 + 79 = (79+79) - (36+42) = 158 - 78 = 80 \)
2. \( 3,19 - 5,9 - 0,86 = 3,19 - (5,9 + 0,86) = 3,19 - 6,76 = -3,57 \)
3. \( 2,4 + (-5,36) - (-0,84) + (-3,24) = 2,4 - 5,36 + 0,84 - 3,24 = (2,4+0,84) - (5,36+3,24) = 3,24 - 8,60 = -5,36 \)
4. \( -16,54 + (-9,31) - 11,27 - (-23,38) = -16,54 - 9,31 - 11,27 + 23,38 = (23,38) - (16,54+9,31+11,27) = 23,38 - 37,12 = -13,74 \)
5. \( 5\frac{3}{7} + \left(-2\frac{1}{4}\right) - \left(-3\frac{3}{28}\right) = 5\frac{3}{7} - 2\frac{1}{4} + 3\frac{3}{28} = \frac{38}{7} - \frac{9}{4} + \frac{87}{28} = \frac{38 \cdot 4}{7 \cdot 4} - \frac{9 \cdot 7}{4 \cdot 7} + \frac{87}{28} = \frac{152}{28} - \frac{63}{28} + \frac{87}{28} = \frac{152 - 63 + 87}{28} = \frac{89 + 87}{28} = \frac{176}{28} = \frac{44}{7} = 6\frac{2}{7} \)
6. \( 3\frac{5}{9} + \left(-2\frac{1}{4}\right) - \left(-4\frac{5}{6}\right) - 5\frac{2}{3} = 3\frac{5}{9} - 2\frac{1}{4} + 4\frac{5}{6} - 5\frac{2}{3} = \frac{32}{9} - \frac{9}{4} + \frac{29}{6} - \frac{17}{3} = \frac{32 \cdot 4}{9 \cdot 4} - \frac{9 \cdot 9}{4 \cdot 9} + \frac{29 \cdot 2}{6 \cdot 2} - \frac{17 \cdot 12}{3 \cdot 12} = \frac{128}{36} - \frac{81}{36} + \frac{58}{12} - \frac{204}{36} = \frac{128}{36} - \frac{81}{36} + \frac{58 \cdot 3}{12 \cdot 3} - \frac{204}{36} = \frac{128}{36} - \frac{81}{36} + \frac{174}{36} - \frac{204}{36} = \frac{128 - 81 + 174 - 204}{36} = \frac{47 + 174 - 204}{36} = \frac{221 - 204}{36} = \frac{17}{36} \)

Ответ: 1) 80; 2) -3,57; 3) -5,36; 4) -13,74; 5) 6\(\frac{2}{7}\); 6) \(\frac{17}{36}\).