1/2+1/6+1/12+1/20+1/30+1/42=?用综合算式1/2+1/6+1/12+1/20+1/30+1/42 = = 巧算 最好简单明了
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![1/2+1/6+1/12+1/20+1/30+1/42=?用综合算式1/2+1/6+1/12+1/20+1/30+1/42 = = 巧算 最好简单明了](/uploads/image/z/66769-25-9.jpg?t=1%2F2%2B1%2F6%2B1%2F12%2B1%2F20%2B1%2F30%2B1%2F42%3D%3F%E7%94%A8%E7%BB%BC%E5%90%88%E7%AE%97%E5%BC%8F1%2F2%2B1%2F6%2B1%2F12%2B1%2F20%2B1%2F30%2B1%2F42+%3D+%3D+%E5%B7%A7%E7%AE%97+%E6%9C%80%E5%A5%BD%E7%AE%80%E5%8D%95%E6%98%8E%E4%BA%86)
1/2+1/6+1/12+1/20+1/30+1/42=?用综合算式1/2+1/6+1/12+1/20+1/30+1/42 = = 巧算 最好简单明了
1/2+1/6+1/12+1/20+1/30+1/42=?用综合算式
1/2+1/6+1/12+1/20+1/30+1/42 = = 巧算 最好简单明了
1/2+1/6+1/12+1/20+1/30+1/42=?用综合算式1/2+1/6+1/12+1/20+1/30+1/42 = = 巧算 最好简单明了
1、这道题要用“分数的拆分法”来解答,就是说把题中的各个分数拆成下面的减法算式,从而形成加减抵消啦.
1/2=1-1/2;
1/6=1/2-1/3;
1/12=1/3-1/4;
1/20=1/4-1/5;
1/30=1/5-1/6;
1/42=1/6-1/7
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
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)-(1/6-1/6)-1...
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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)-(1/6-1/6)-1/7
=1-0-0-0-0-0-1/7
=6/7 更简单写的方法是
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
收起
=1/2+1/2*3+1/3*4+1/4*5+1/5*6+1/6*7
=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7
=1-1/7
=6/7
自己算,傻瓜! 我当然狠你了,笨蛋!
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