1/3+1/12+1/20+1/30+1/42+1/56=?写出简算过程
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![1/3+1/12+1/20+1/30+1/42+1/56=?写出简算过程](/uploads/image/z/141993-9-3.jpg?t=1%2F3%2B1%2F12%2B1%2F20%2B1%2F30%2B1%2F42%2B1%2F56%3D%3F%E5%86%99%E5%87%BA%E7%AE%80%E7%AE%97%E8%BF%87%E7%A8%8B)
1/3+1/12+1/20+1/30+1/42+1/56=?写出简算过程
1/3+1/12+1/20+1/30+1/42+1/56=?
写出简算过程
1/3+1/12+1/20+1/30+1/42+1/56=?写出简算过程
注确定第一项是1/3吗
1/3+1/12+1/20+1/30+1/42+1/56
=1/3+1/3x4+1/4x5+1/5x6+1/6x7+1/7x8
=1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8
=1/3+1/3-1/8 (中间的正负抵消了)
=16/24-3/24
=13/24