Question

1-3+5-7+9-11+13.+2001答案是多少

Answer 1

1 - 3 + 5 - 7 + 9 - 11 + 13 - 15 +... + 2001

= (1 - 3) + (5 - 7) + (9 - 11) + (13 - 15) + ... + (1997 - 1999) + 2001

= (-2) × 500 + 2001

= -1000 + 2001

= 1001