作业帮1、345×998（简算,2、5/8+1又7/10-0.4-0.7（简算,3、0.75×14又1/9+3/4×1又8/9-12×75%（简算,4、[（10-1÷25）÷9.6]×0.01（脱式计算,5、x-1/2x-1=4/9（解方程,
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![1、345×998（简算,2、5/8+1又7/10-0.4-0.7（简算,3、0.75×14又1/9+3/4×1又8/9-12×75%（简算,4、[（10-1÷25）÷9.6]×0.01（脱式计算,5、x-1/2x-1=4/9（解方程,](/uploads/image/z/5157177-33-7.jpg?t=1%E3%80%81345%C3%97998%EF%BC%88%E7%AE%80%E7%AE%97%2C2%E3%80%815%2F8%2B1%E5%8F%887%2F10-0.4-0.7%EF%BC%88%E7%AE%80%E7%AE%97%2C3%E3%80%810.75%C3%9714%E5%8F%881%2F9%2B3%2F4%C3%971%E5%8F%888%2F9-12%C3%9775%25%EF%BC%88%E7%AE%80%E7%AE%97%2C4%E3%80%81%5B%EF%BC%8810-1%C3%B725%EF%BC%89%C3%B79.6%5D%C3%970.01%EF%BC%88%E8%84%B1%E5%BC%8F%E8%AE%A1%E7%AE%97%2C5%E3%80%81x-1%2F2x-1%3D4%2F9%EF%BC%88%E8%A7%A3%E6%96%B9%E7%A8%8B%2C)
1、345×998（简算,2、5/8+1又7/10-0.4-0.7（简算,3、0.75×14又1/9+3/4×1又8/9-12×75%（简算,4、[（10-1÷25）÷9.6]×0.01（脱式计算,5、x-1/2x-1=4/9（解方程,
1、345×998（简算,
2、5/8+1又7/10-0.4-0.7（简算,
3、0.75×14又1/9+3/4×1又8/9-12×75%（简算,
4、[（10-1÷25）÷9.6]×0.01（脱式计算,
5、x-1/2x-1=4/9（解方程,
1、345×998（简算,2、5/8+1又7/10-0.4-0.7（简算,3、0.75×14又1/9+3/4×1又8/9-12×75%（简算,4、[（10-1÷25）÷9.6]×0.01（脱式计算,5、x-1/2x-1=4/9（解方程,
1 345*1000-345*2等于345000-690等于344310
2 （0.625-0.4）+（1.7-0.7)等于0.225+1等于0.225
3 原式=3/4×14又1/9+3/4×1又8/9-12×3/4=3/4×(14又1/9+1又8/9-12)=3/4×4=3
4前边是10.1还是10—1 看不清楚
5 x-1/2x-1=4/9
1/2x-1=4/9
1/2x=13/9
x=26/9
可怜的娃，题偶们都会，但这也太难打了吧！分还这么低.........
我都不知道你在说什么 又是什么
1、345*1000-345*2等于345000-690等于344310
2、（0.625-0.4）+（1.7-0.7)等于0.225+1等于0.225
3、
分也太少了吧 ,给多点分,我都会
。
1、345×998
=345×（1000-2）
=345×1000-345×2
=345000-690
=344310
2、5/8+1又7/10-0.4-0.7
=5/8-2/5(就是0.4)+（17/10(就是1又7/10)-7/10（就是0.7））
=7/40+1
=1又7/40
3、0.75×14又1/9+3...
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1、345×998
=345×（1000-2）
=345×1000-345×2
=345000-690
=344310
2、5/8+1又7/10-0.4-0.7
=5/8-2/5(就是0.4)+（17/10(就是1又7/10)-7/10（就是0.7））
=7/40+1
=1又7/40
3、0.75×14又1/9+3/4×1又8/9-12×75%
=0.75×127/9+0.75×17/9-12×0.75
=0.75×(127/9+17/9-12)
=0.75×4
=3
4、[（10-1÷25）÷9.6]×0.01
=[9.96÷9.6]×0.01
=1.0375×0.01
=0.010375
5、 x-1/2x-1=4/9
（1-1/2）x-1=4/9
1/2x-1=4/9
1/2x=13/9
x=26/9
望采纳，谢谢！
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