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速算与巧算,急啊!1. 1.999+2.998+3.997+4.996+.+999.001 =2. (44332-443

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速算与巧算,急啊!
1. 1.999+2.998+3.997+4.996+.+999.001
=
2. (44332-443.32)/(88664-886.64)
=
满意追加100分!
速算与巧算,急啊!1. 1.999+2.998+3.997+4.996+.+999.001 =2. (44332-443
1.1.999+2.998+3.997+4.996+.+999.001
=(1.999+999.001)+(2.998+999.002)+(3.997+999.003)+……+(499.499+501.501)+500.5
=1001×499+500.5
=499999.5
2.(44332-443.32)/(88664-886.64)
假设 443.32=x 那么44332=100x 886.64=2x 88664=200x
所以原式变成 (100x-x)/(200x-2x)
=99x/198x
=0.5