Номер 1183

1) – 2 + 3 – 7 + 9 = – 2 + (3 – 7 – 9)

2) a – b + c – d = a + (–b + c – d)

3) –p – 2,5 – c + d = –p + (–2,5 – c + d)

4) 7,2 – a – b – c = 7,2 + (–a – b – c)