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1、4/5×1/2+2/5÷0.6-1/15

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/08/29 20:47:07
1、4/5×1/2+2/5÷0.6-1/15
2、 1/1×3+1/3×5+1/5×7+.+1/17×19+1/19×21
3、 9999×2222+3333×3334
4、【(8 又5/8-4.625)÷(2.4+1又3/5)】×50%
4/5×1/2+2/5÷0.6-1/15
=2/5+10/15-1/15
=6/15+10/15-1/15=1
1/1×3+1/3×5+1/5×7+.+1/17×19+1/19×21
=1/2×(1-1/3+1/3-1/5+1/5-1/7.+1/19-1/21)
=1/2×(1-1/20)
=10/21
9999*2222+3333*3334
=3333×3×2222+3333×3334
=3333×6666+3333×3334
=3333×(6666+3334)
=3333×10000
=33330000
【(8 又5/8-4.625)÷(2.4+1又3/5)】×50%
=【(8又5/8-4又5/8)÷(2.4+1.6)】×0.5
=【4÷4】×0.5
=0.5