5分之4除以9又5分之4除以99又5分之4除以999又5分之4除以9999又5分之4如何计算
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5分之4除以9又5分之4除以99又5分之4除以999又5分之4除以9999又5分之4如何计算
4/5÷9右4/5÷99右4/5÷999右4/5÷9999右4/5
=(5-1)/5x5/(50-1)x5/(500-1)x5/(5000-1)x5/(50000-1)
=(5-1)x5/(50-1)(50000-1)x25/(500-1)(5000-1)
=20/(2500000-50000-50+1)x25/(2500000-5000-500+1)
=500/[(2450000-49)x(2494500+1)]
=500/[(6111525000000-122230500-2450000-49)]
=500/611140031951
5*9+4=5*10-1=49(4后面加乘9个数个9)
(用倒数变成乘法,再把5分之4和49分只5化简)
49*499=(49+1)*(499+1)-(49+499+1)=24451
4999*49999=(4999+1)*(49999-1)-(4999+49999+1)=249945001
24451*249945001=24551*200000000+24551...
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5*9+4=5*10-1=49(4后面加乘9个数个9)
(用倒数变成乘法,再把5分之4和49分只5化简)
49*499=(49+1)*(499+1)-(49+499+1)=24451
4999*49999=(4999+1)*(49999-1)-(4999+49999+1)=249945001
24451*249945001=24551*200000000+24551*40000000+24551*9000000+24551*900000*24551*40000*+24551*5000+24551=6111405219451
4*5*5*5=250
答案=6111405219451分之250
(PS:不知对不对,而且不知到够不够简洁)
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