Odpowiedzi

2013-08-14T07:59:21+02:00
1 - 2 + 3 - 4 + 5 - 6 + 7 - 8 + ... + 1499 - 1500
= (1 - 2) + (3 - 4) + (5 - 6) + ... + (1499 - 1500)
= -1 + (-1) + (-1) + (-1) + ... + (-1)
= 1500 : 2 * (-1) = 750 * (-1) = -750
1 5 1