Question

简算题：1x2/1+2x3/1+3x4/1+4x5/1+5x6/1+6x7/1+7x8/1+8x9/1

过程写清楚。

Answer 1

估计楼主的题目出错了
是不是：
1x1/2+2x1/3+3x1/4+4x1/5+5x1/6+6x1/7+7x1/8+8x1/9
＝1/2+2/3+3/4+4/5+5/6+6/7+7/8+8/9
=33/12+4/5+6/7+7/8+8/9
=22/8+7/8+4/5+6/7+8/9
=29/8+4/5+6/7+8/9
=177/40+6/7+8/9
1479/280+8/9
=14511/1520

Answer 2

1x2/1+2x3/1+3x4/1+4x5/1+5x6/1+6x7/1+7x8/1+8x9/1
=1x2+2x3+3x4+4x5+5x6+6x7+7x8+8x9
=2+6+12+20+30+42+56+72
=20+50+170
=70+170
=240