简算题:（1/8+1/24+1/48+1/80+1/120+1/168+1/224+1/288）×128

数学题解答：把括号中每个加数，提取1/4，

得到：(1/2+1/6+1/12+1/20+……+1/72)×1/4×128

括号里面的你会算吗？1/2=1 – 1/2，1/6=1/2 – 1/3，1/12= 1/3 – /1/4，……

原式＝(1/2+1/6+1/12+1/20+……+1/72) × 1/4 × 128

＝(1 – 1/2 + 1/2 – 1/3 +1/3 – ……- 1/8 + 1/8- 1/9) × 1/4 × 128

＝8/9 × 32

＝256/9

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