幫我回答一下題目(簡便方法計算) 33333×6×11111+222222 1/2+1/6+1/12+1/30+1/42
題目:
幫我回答一下題目(簡便方法計算) 33333×6×11111+222222 1/2+1/6+1/12+1/30+1/42+1/56
還有999×888+888×777+777×666+666×555
解答:
33333×6×11111+222222
=33333*3*2*11111+200000+22222
=22222*(99999+1)+200000
=2222200000+200000
=2222400000
1/2+1/6+1/12+1/20+1/30+1/42+1/56 原式缺了+1/20
=1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8
=1-1/8
=7/8
999×888+888×777+777×666+666×555
=9*111*8*111+8*111*7*111+7*111*6*111+6*111*5*111
=(9*8+8*7+7*6+6*5)*111*111
=200*111*111
=2464200
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