(1) -二分之一-[0.75除以(0.25-5乘以二分之一)]
(2) -4除以[(1-三分之二)+12乘以(負八分之三)]
要列式呀''
幫幫我~plz
兩條數學問題~急!!!!!!!!!!!!!!20marks~~~
2008-09-25 4:52 am
回答 (3)
2008-09-26 2:34 am
✔ 最佳答案
1. 1/2-[0.75除以(0.25-2.5)]=-1/2-(0.75除以-2 1/4)
=-1/2-(3/4除以-2 1/4)
=-1/2+1/3
=5/6
2. 4除以[(1-2/3)+12x(-3/8)]
=4除以[1/3+(-9/2)]
=4除以(-25/6)
=-(4x6/25)
=-24/25
參考: me
2008-09-25 6:09 am
先張所有數變為分數,
計算分數加減時再通分母,
會做的比較簡單~^^
(1) -1/2-[(3/4)/(1/4-5x1/2)]
=-1/2-[(3/4)/(-9/4)]
=-1/2-[(3/4)x(-4/9)]
=-1/2+(-1/3)
=-1/6
(2) -4/[(1-2/3)+12x(-3/8)]
=-4/[1/3-/2]
=-4/[2/6-8/6]
=-4x-(6/16)
=2/3
2008-09-24 22:10:10 補充：
唔好意思,第一題最後計錯左,
應該係-5/6
計算分數加減時再通分母,
會做的比較簡單~^^
(1) -1/2-[(3/4)/(1/4-5x1/2)]
=-1/2-[(3/4)/(-9/4)]
=-1/2-[(3/4)x(-4/9)]
=-1/2+(-1/3)
=-1/6
(2) -4/[(1-2/3)+12x(-3/8)]
=-4/[1/3-/2]
=-4/[2/6-8/6]
=-4x-(6/16)
=2/3
2008-09-24 22:10:10 補充：
唔好意思,第一題最後計錯左,
應該係-5/6
參考: ME
2008-09-25 5:17 am
=-1/2-[0.75除以(0.25-2.5)]
=-1/2-(0.75除以-2 1/4)
=-1/2-(3/4除以-2 1/4)
=-1/2+1/3
=-?(唔記得點做)
=-1/2-(0.75除以-2 1/4)
=-1/2-(3/4除以-2 1/4)
=-1/2+1/3
=-?(唔記得點做)
收錄日期: 2021-04-19 20:31:27
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