应该是1/2=1-1/2，1/6=1/2-1/3…
把上面的信息代入下式：
得1-1/2+1/2-1/3+1/3-1/4…+1/6-1/7
=1-1/7
=6/7
1/2＋1/6＋1/12＋1/20＋1/30＋1/42
＝(1-1/2)＋(1/2-1/3)＋(1/3-1/4)＋(1/4-1/5)＋(1/5-1/6)＋(1/6-1/7)
＝1-1/7＝6/7
原式=1-1/2+1/2-1/3+1/3-1/4+
1/4-1/5+1/5-1/6+1/6-1/7
＝1-1/7＝6/7
1\/2=1-1\/2,1\/6=1\/2-1\/3,1\/12=1\/3-1\/4...请根据以上的规律计算:1\/6+1\/...
解：1\/6+1\/12+1\/20+1\/30+1\/42 =（1\/2-1\/3）+（1\/3-1\/4）+（1\/4-1\/5）+（1\/5-1\/6）+（1\/6-1\/7）=1\/2-1\/3+1\/3-1\/4+1\/4-1\/5+1\/5-1\/6+1\/6-1\/7 =1\/2-（1\/3-1\/3）-（1\/4-1\/4）-（1\/5-1\/5）-（1\/6-1\/6）-1\/7 =1\/2-0-0-0-0-1\/7...
...根据上述规律计算下题:1\/2+1\/6+1\/12+1\/20+1\/30=
=1-1\/2+1\/2-1\/3+1\/3-1\/4+1\/4-1\/5+1\/5-1\/6 =1-1\/6 =5\/6
计算: 1÷(1\/2+1\/6+1\/12+1\/20...+1\/342+1\/380)=?
1\/6=1\/2-1\/3 1\/12=1\/3-1\/4 ……1\/342=1\/18-1\/19 1\/380=1\/19-1\/20 这些相加就是1-1\/20=19\/20 所以答案是20\/19
简便计算1\/2+1\/6+1\/12+1\/20+1\/30+1\/42?
原式=6\/7 解题分析 将分母6、12、20、30、42分解为2×3、3×4、4×5、5×6、6×7，然后再化简。1\/2+1\/6+1\/12+1\/20+1\/30+1\/42 =1\/2+1\/（2×3）+1\/（3×4）+1\/（5×6）+1\/（6×7）=1\/2+（1\/2-1\/3）+（1\/3-1\/4）+（1\/5-1\/6）+（1\/6-1\/7）=1\/2+1...
1\/2+1\/6+1\/12+1\/20+1\/30+1\/42的简便运算。
1\/2+1\/6+1\/12+1\/20+1\/30+1\/42 =1\/(1x2)+1\/(2x3)+1\/(3x4)+1\/(4x5)+1\/(5x6)+1\/(6x7)=(1 -1\/2) +(1\/2-1\/3)+...+(1\/6-1\/7)=1 -1\/7 =6\/7 异分母分数相加：1、异分母分数相加，先通分，再按同分母分数相加法去计算，最后要化成最简分数。例1：3\/4+5\/7...
求1\/2+1\/6+1\/12+1\/20...+1\/2450的计算答案,要具体算式。谢谢!
因为 1\/2=1-1\/2 1\/6=1\/2-1\/3 1\/12=1\/3-1\/4 ...1\/2450=1\/49-1\/50 所以原式=1-1\/2+1\/2-1\/3...+1\/49-1\/50 =1-1\/50=49\/50
1\/2+1\/6+1\/12+1\/20+1\/30+1\/42的简便运算?
1\/6，1\/12这三个数分母通分都为12。1\/20，1\/30分母通分为60。所以，简便运算先算前三个数和最后一个数。原=1\/2+1\/6+1\/12+1\/42+1\/20+1\/30 =6\/12+2\/12+1\/12+1\/42+3\/60+2\/60 =9\/12+1\/42+5\/60 =9\/12+1\/42+1\/12 =10\/12+1\/42 =70\/84+2\/84 =72\/84 =6\/7 ...
1\/2+1\/6+1\/12+1\/20+1\/30+1\/42的简便运算?
【为通分重新组合】=(1\/2+1\/6+1\/12)+(1\/20+1\/30)+1\/42 =(6+2+1)\/12 +(3+2)\/60 +1\/42 =9\/12 +5\/60 +1\/42 【分数约分】=(9\/12 +1\/12) +1\/42 =10\/12 +1\/42 【约分】=5\/6 +1\/42 【通分】=35\/42 +1\/42 =36\/42 【约分】=6\/7 ...
二分之一加六分之一加十二分之一加二十分之一的简便算法
=1\/2+1\/2-1\/3+1\/3-1\/4+1\/4-1\/5+1\/5-1\/6+...+1\/99-1\/100。=1-1\/100。=99\/100。分5261子表示分数中写在分数线上面的数。一般情4102况下，分子为整数，当分子不为整数时，需利用分数的基本性质将其化为整数。分母是已知数的分数叫整式，分母是未知数的分数叫分式。分母应该不能...
1\/2+1\/6+1\/12+1\/20+1\/30+1\/42=多少 过程
1\/2+1\/6+1\/12+1\/20+1\/30+1\/42 =（1-1\/2）+（1\/2-1\/3）+（1\/3-1\/4）+（1\/4-1\/5）+（1\/5-1\/6）+（1\/6-1\/7）=1-1\/2+1\/2-1\/3+1\/3-1\/4+1\/4-1\/5+1\/5-1\/6+1\/6-1\/7 =1-（1\/2-1\/2）-（1\/3-1\/3）-（1\/4-1\/4）-（1\/5-1\/5）-（1\/6-1...
