解方程 x+5/6=5/2 x-3/4=2/3 9/7-x=2/5
1\/2+2\/3-5\/6+7\/12-2\/15-4\/21-12\/35简便方法
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简便方法计算1+2-3-4+5+6-7-8+9+10-11-12+13+14-15-16+17+18-19-20...
1,2,3,4为一组;5,6,7,8为一组,,,依次类推,这样分成了5组还余下了21和22两个数。被分组的各族数字都有这样的一个特点,即后边两个数的和与前面两个数的和之差都是4,照样5组算下来计算结果为(-4)*5=-20 所以最后结果就是21+22-20咯 ...
(1\/2+1\/3+1\/4+1\/5+1\/6+1\/7+1\/8+1\/9+1\/10+1\/11+1\/12+1\/13+1\/14+1\/15...
最后变成(1+3+4+...+14)\/2=52.5
1\/2+3\/4+5\/6+7\/8+9\/10+11\/12+13\/14+15\/16+17\/18+19\/20 值 求讲解
=10-(1\/2+1\/4+1\/8+1\/10+1\/12+1\/14+1\/16+1\/18+1\/20)=10-(1\/2+1\/4+1\/8++1\/16+1\/12+1\/18+1\/14+1\/10+1\/20)=10-(155\/144+31\/140)=10-(6541\/5040)=8又3539\/5040
简便 算法1+2+3+4+5+6+7+8+9+10+12+13+14+15+161+17+18+19+20+21+22...
1+2+3+4+5+6+7+8+9+10+12+13+14+15+161+17+18+19+20+21+22+23+24+25+26+27+28+29+30 =(1+30)×(30÷2)=31×15 =465
1\/3+3\/4+2\/5+5\/7+7\/8+9\/20+10\/21+11\/24+12\/35怎么简算
如下:1\/3+3\/4+2\/5+5\/7+7\/8+9\/20+10\/21+11\/24+12\/35 =1\/3+3\/4+2\/5+5\/7+7\/8+1\/4+1\/5+1\/3+1\/7+1\/3+1\/8+1\/5+1\/7 =4\/5 小学数学简便方法归纳 1、提取公因式:这个方法实际上是运用了乘法分配律,将相同因数提取出来,考试中往往剩下的项相加减,会出现一个整数。...
1+2+3-4-5-6+7+8+9-10-11-12+...+2019-2020-2021-2022等于多少
计算过程如下:1+2+3-4-5-6+7+8+9-10-11-12+...+2019-2020-2021-2022 =(1+2+3-4-5-6)+(7+8+9-10-11-12)+...+(2017+2018+2019-2020-2021-2022)=-6x337 =-2022 加法运算性质:从加法交换律和结合律可以得到:几个加数相加,可以任意交换加数的位置;或者先把几个加数...
简便计算:1-2+3-4+5-6+…+99-100+101(要有过程)?
从1到101有51个奇数,5o个偶数,1除外每个奇数都比每个偶数大1,那么50个数正好奇数减偶数为50,加上1为51。列式为:(3十5十7……一2一4一6……)十1=51
...+3\/4-5\/8 4\/5-(3\/10+1\/6) 5\/9+7\/18+4\/9 1-2\/7-5\/7
5\/6-1\/2+1\/4 =5\/6-1\/4 =10\/12-3\/12;=7\/12;5\/12+3\/4-5\/8 =10\/24+18\/24-15\/24 =13\/24;4\/5-(3\/10+1\/6)=24\/30-9\/30-5\/30 =10\/30 =1\/3;5\/9+7\/18+4\/9 =(5\/9+4\/9)+7\/18 =1+7\/18 =25\/18;1-2\/7-5\/7 =1-(2\/7+5\/7)=1-1 =0 2\/3+5\/...
...1\/2+1\/3-1\/4)X24 4\/9X1\/6+5\/9除6 4\/7-3\/7除15\/14
=2\/3-1\/2+5\/6 =4\/6-3\/6+5\/6 =6\/6 =1 (1\/2+1\/3-1\/4)X24 =1\/2 x24 +1\/3 x24- 1\/4x24 =12+8-6 =14 4\/9X1\/6+5\/9除6 =4\/9X1\/6+5\/9X1\/6 =(4\/9+5\/9)X1\/6 =9\/9X1\/6 =1\/6 4\/7-3\/7除15\/14 =4\/7-3\/7 x14\/15 =4\/7-2\/5 =20\/35-14\/35...