Номер 1101
1) 4/19 + (–5/19) + 7/19 + (–13/19) = (4 + 7 – 5 – 13)/19 = –7/19
2) 12/3 + (–8/17) + 51/3 + (–9/17) = 12/3 + 51/3 + ((–8/17) + (–9/17)) = 7 + (–1) = 6
3) –5 1/7 + 4 4/7 + 2 6/7 + (–1 2/7) = –5 1/7 + (–1 2/7) + (4 4/7 + 2 6/7) = –6 3/7 + 6 10/7 = –6 3/7 + 7 3/7 = 1
4) 9 1/11 + 5 7/13 + (–8 3/11) + (–5 7/13) = 8 12/11 + (–8 3/11) = 9/11