Номер 1096

1) –9 + 6 + (–6) + 9 = (–9 + 9) + (6 + (–6)) = 0;

2) 42 + (–10) + (–39) + 10 = 42 + (–39) + (–10) + 10 = 3;

3) –2,63 + 5,28 + 1,72 + (–8,73) = –2,63 + (–8,37) + (5,28 + 1,72) = –11 + 7 = –4;