1x2=1|3(1x2x3-0x1x2) 2x3=1|3(2x3x4-1x2x3) 3x4=1|3(3x4x5-2x3x4)由此推断1x2x3+2x3x4+3x4x5....7x8x9=?

2024-12-14 02:49:46
推荐回答(2个)
回答1:

3*(1x2+2x3+3x4+...+99x100)
=3*1/3*(1x2x3-0x1x2+2x3x4-1x2x3+3x4x5-2x3x4+99x100x101-98x99x100)
=99x100x101

回答2:

99x100x101