2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1,简便运算,

来源：学生作业帮助网 编辑：作业帮 时间：2024/05/11 17:29:51
2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1,简便运算,

2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1,简便运算,
2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1,简便运算,

2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1,简便运算,
2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1
=1-2/1+2/1-3/1+3/1-4/1+4/1-5/1+5/1-6/1+6/1-7/1+7/1-8/1+8/1-9/1+9/1-10/1
=1-10/1
=10/9

2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1
=1-2/1+2/1-3/1+3/1-4/1+4/1-5/1+5/1-6/1+6/1-7/1+7/1-8/1+8/1-9/1+9/1-10/1
=1-10/1
=10/9
给分

2%1+6%1+12%1+20%1+30%1 1/2+1/6+1/12+1/20+1/30 1/2,-1/6,1/12,-1/20,1/30 1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72 1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72 1+1/2+1/12+1/6+1/20+1/30+1/40+1/56 1+1/2+1/6+1/12+1/20+1/30.+1/901+1/2+1/6+1/12+1/20+1/30+.+1/90简便计算 1/2+1/6+1/12+1/20+1/30+1/42+1/56 简算 1/2+1/6+1/12+1/20+1/30+1/42+1/56简算, 简便运算：1/2+1/6+1/12+1/20+1/30+1/42+1/56 1+1/2+1/6+1/12+1/20+1/30+1/42的简便计算 2/1+6/1+12/1+20/1+30/1+42/1+56/1=? 1/2 - 1/6 - 1/12 - 1/20 - 1/30 - 1/42 - 1/56怎么算 1/2+1/6+1/12+1/20+1/30+.1/380+1/420= 1+1/2+1/6+1/12+1/20+1/30+1/42=? 1/2+1/6+1/12+1/20+1/30+1/42+1/56 1/2-1/6-1/12-1/20-1/30-1/42-1/56等于多少 2/1+6/1+12/1+20/1+30/1+42/1+56/1=