F.1數
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(-30)(+12)(-8)
---------------------- ＜－－分線
(+18)(-5)
步驟＋文字說明
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A son's age 1/4 of his father's age now. Three years ago, the son was 5 years old. How old is the father now?
方程
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F.1數學
2007-08-27 1:39 am
回答 (5)
2007-08-27 2:15 am
(-30)(+12)(-8)
1. ------------------------
(-18)(-5)
(-360)(-8)
=----------------- (-30)(+12)=(-360) 因為負正得負 , (-18)(-5)=(-90) 因為負負得正
(-90)
2880
=------------ (-360)(-8)=2880 因為負負得正
(-90)
288
=--------- 2880=288 , (-90)=(-9) 因為2880同(-90)大家相約個 0
(-9)
= -32 最後再相除 , 就得到 -32 這答案
2.設他爸今年他爸爸已經x歲
x
5+3 = -----
4
x
8= -----
4
x= 32
今年他爸爸已經32歲
1. ------------------------
(-18)(-5)
(-360)(-8)
=----------------- (-30)(+12)=(-360) 因為負正得負 , (-18)(-5)=(-90) 因為負負得正
(-90)
2880
=------------ (-360)(-8)=2880 因為負負得正
(-90)
288
=--------- 2880=288 , (-90)=(-9) 因為2880同(-90)大家相約個 0
(-9)
= -32 最後再相除 , 就得到 -32 這答案
2.設他爸今年他爸爸已經x歲
x
5+3 = -----
4
x
8= -----
4
x= 32
今年他爸爸已經32歲
2007-08-27 1:59 am
1. (-30)(+12)(-8)
---------------------- ＜－－分線
(+18)(-5)
= -(30x12)(-8)
-----------------------
-(18x5)
= (-360)(-8)
-----------------
-90
= +(360x8)
---------------
-90
= 2880
--------
-90
= -32
Note : (+)(+) =(+)
(-) (-) =(+)
(+)( -) =(-)
( -)(+) =(-)
2 . Let y be the age of father now.
1/4y =5+3
---------------------- ＜－－分線
(+18)(-5)
= -(30x12)(-8)
-----------------------
-(18x5)
= (-360)(-8)
-----------------
-90
= +(360x8)
---------------
-90
= 2880
--------
-90
= -32
Note : (+)(+) =(+)
(-) (-) =(+)
(+)( -) =(-)
( -)(+) =(-)
2 . Let y be the age of father now.
1/4y =5+3
2007-08-27 1:55 am
1. (-30)(+12)(-8) / (+18)(-5)
= 2880/ -90
= -32
把數乘埋就得
2. Let the age of his father is x
5+3 = x/4
8= x/4
x= 32
三年前5歲, 即今年8歲, 而今年他是他爸的1/4
= 2880/ -90
= -32
把數乘埋就得
2. Let the age of his father is x
5+3 = x/4
8= x/4
x= 32
三年前5歲, 即今年8歲, 而今年他是他爸的1/4
2007-08-27 1:53 am
1. (-30)(+12)(-8) / (+18)(-5) = 2880/-90=-32
2. Let x be the age of son now.
Father age now = x/(1/4) = 4x
x-3=5
x=8
hence, father age now = 4*8=32
2. Let x be the age of son now.
Father age now = x/(1/4) = 4x
x-3=5
x=8
hence, father age now = 4*8=32
2007-08-27 1:44 am
2280
______
-90
= -32
______
-90
= -32
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原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070826000051KK03079