1. 1+2+3+4+5+6+7+8+7+6+5+4+3+2+1 2×(1+2+3+4+5+6+7+8)-8
———————————————= ———————————————
888888×888888 888888×888888
64 1 1
= ———————— = ———————— = ——————--
888888×888888 111111×111111 12345654321
2. (2\2002+4\2002+6\2002+……+2002\2002)-(1\2002+3\2002+5\2002+2001\2002)
=(-1+2-3+4-……-2001+2002)/2002
=1001/2002
=1/2.
1+2+3+4+5+6+7+8+7+6+5+4+3+2+1
———————————————
888888×888888
8*8
=--------------------------
888888×888888
1
=------------------------
111111*111111
1
=------------------------
12345654321
注:111..11*111..**是个公式,例如11*11=121,111*111=12321
2.(2\2002+4\2002+6\2002+……+2002\2002)-(1\2002+3\2002+5\2002+2001\2002)
=2/2002-1/2002+....+2002/2002-2001/2002
=1001*1/2002
=1001/2002
=1/2
1+2+3+4+5+6+7+8+7+6+5+4+3+2+1
———————————————
888888×888888
8*8
=--------------------------
888888×888888
1
=------------------------
111111*111111
1
=------------------------
12345654321
(2\2002+4\2002+6\2002+……+2002\2002)-(1\2002+3\2002+5\2002+2001\2002)
=(-1+2-3+4-……-2001+2002)/2002
=1001/2002
=1/2.