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標題: Maths. Questions [打印本頁]

作者: 細薯 時間: 30/8/2004 09:12 AM
標題: Maths. Questions
This is some questions in my Summer Vacation Exercise

Factorize:

(a)  2x^2 + 3xy + y^2

(b)  3p^2 - 7pq - 6q^2

(c)  5a^2 + 7ab + 2b^2

(d)  4c^2 + 4cd - 24d^2

*  c^2=c的二次方

help me please~

[ Last edited by smallpotato226 on 2004-8-30 at 10:22 AM ]

作者: Echo21 時間: 30/8/2004 09:57 AM

smallpotato226  在 2004-8-30 09:12 發表:

This is some questions in my Summer Vacation Exercise

Factorize:

(a)  2x^2 + 3xy + y^2

(b)  3p^2 + - 7pq - 6q^2

(c)  5a^2 + 7ab + 2b^2

(d)  4c^2 + 4cd - 24d^2

*  c^2=c的 ...

最差的就是Factorization.....
D：
4(c^2+cd-6d^2)
是不是這樣？？

作者: WZero 時間: 30/8/2004 10:11 AM
(a)  2x^2 + 3xy + y^2 = (2x+y)(x+y)

(b)  3p^2+ - 7pq- 6q^2 = (3p+2q)(p-3q)

(c)  5a^2 + 7ab + 2b^2 = (5a+2b)(a+b)

(d)  4c^2 + 4cd - 24d^2 = 4(c^2 + cd - 6d^2) = 4(c+3d)(c-2d)

作者: rogergeot 時間: 30/8/2004 10:14 AM
(a). 2x^2+3xy+y^2
   =(2x+y)(x+y)
(c). 5a^2+7ab+2b^2
   =(5a+2b)(a+b)
(d).  4c^2+4cd-24d^2
   =(2c-4d)(2c+6d)
   =2(c-2d)2(c+3d)
   =4(c-2d)(c+3d)

I do not know what do you mean by +-7pq in question b.
Too bad someone answer the question faster than me... I was typing too slow.

[ Last edited by rogergeot on 2004-8-30 at 10:15 AM ]

作者: 細薯 時間: 30/8/2004 10:22 AM
i have got some mistake~
corrected

Echo21 在 2004-8-30 09:57 AM 發表:
最差的就是Factorization.....

我也是.....

+++++++++++++++++++++++++++++++++

after i read the answer above,
I remember the method to do la~~

thx every body~~

PS:我D功課只下50page maths ja~~~要繼續努力~~

thx a lot~

[ Last edited by smallpotato226 on 2004-8-30 at 10:26 AM ]

作者: Echo21 時間: 30/8/2004 10:32 AM

rogergeot  在 2004-8-30 10:14 發表:

(a). 2x^2+3xy+y^2
   =(2x+y)(x+y)
(c). 5a^2+7ab+2b^2
   =(5a+2b)(a+b)
(d).  4c^2+4cd-24d^2
   =(2c-4d)(2c+6d)
   =2(c-2d)2(c+3d)
   =4(c-2d)(c+3d)

I do not know what do you  ...

可否詳解一下
不太懂
（死得，還要讀A.MATH）

作者: rogergeot 時間: 30/8/2004 10:47 AM
Well.. I am not good at maths... but I will try my best...
Usually when we do factorization, for example: a) 2x^2 + 3xy + y^2, the answer should be something like: ? (?x add or subtract ?y)(?x add or subtract ?y). (like the answer in a)
We first list out all of the factors of 2x^2 and y^2 first:
Factors of 2x^2: 2x and x, -2x and -x
Factors of y^2: y and y, -y and -y
Then, we try to times and add the combination of factors which would give the result of 3xy:
2x times y add x times y = 2xy+xy = 3xy
So, the answer should be (2x+y)(x+y).

I hope that my explanation would not confuse you more.

作者: 抹茶可樂 時間: 30/8/2004 10:54 PM
我好懶的…做暑期作業果陣一定用cal計出來

作者: yat 時間: 30/8/2004 10:55 PM
F.2上學期數黎

作者: oscar 時間: 30/8/2004 11:46 PM

yat 在 2004-8-30 22:55 發表:

F.2上學期數黎

下？我要form3先教...不過我一早識~
奇怪既就係，點解大家唔用交叉法黎搵？

作者: yat 時間: 31/8/2004 01:20 AM

oscar 在 2004-8-30 23:46 發表:

下？我要form3先教...不過我一早識~
奇怪既就係，點解大家唔用交叉法黎搵？

我form2上學期學~
而家乜都唔記得~XD

作者: 細薯 時間: 31/8/2004 10:49 AM

oscar 在 2004-8-30 11:46 PM 發表:

下？我要form3先教...不過我一早識~
奇怪既就係，點解大家唔用交叉法黎搵？

忘記了這方法......=.=

作者: lkw922 時間: 11/9/2004 08:18 AM
呢d係咪會考d數學？

作者: 細薯 時間: 11/9/2004 08:41 AM

lkw922 在 2004-9-11 08:18 AM 發表:

呢d係咪會考d數學？

HKCEE's question are more difficult.....

作者: 幻藍 時間: 11/9/2004 10:07 AM
smallpotato226 好似F.4

作者: 霏 時間: 11/9/2004 05:25 PM
ＨＫＣＥＥ其實唔難，係煩
份卷要

作者: 細薯 時間: 11/9/2004 05:40 PM

可愛的兔兒 在 2004-9-11 10:07 AM 發表:

smallpotato226 好似F.4

yes~what's the matter?!

[quote]幻將在 2004-9-11 05:25 PM 發表:

ＨＫＣＥＥ其實唔難，係煩
份卷要

作者: 霏 時間: 11/9/2004 06:03 PM

smallpotato226 在 2004-9-11 05:40 PM 發表:
你Form幾?
我好同意有時D Exam/Test 不難
是Time ge 問題
不過Math都會唔夠時間?
那我一定要練下D speed sin 得

我學校考試測驗考試都難過ＨＫＣＥＥ
ＨＫＣＥＥ　ｇａｒ　Ｍａｔｈｓ　ＭＣ最容易做唔晒
我最高速都只係淨１５分鐘〔成績係＝．＝錯左唔題．．．最差ｇａｒ一次〕
Ｐａｐｅｒ　Ｉ好少少～但係差唔多冇時間諗

Ａ．Ｍａｔｈｓ就弊小小，因為連Ｍａｔｈｓ　ｇａｒ題目都出得
所以．．．我試過做唔晒

我係ｆｏｒｍ　５

[ Last edited by 幻將 on 2004-9-11 at 06:05 PM ]

作者: oscar 時間: 11/9/2004 08:59 PM

幻將在 2004-9-11 18:03 發表:

我學校考試測驗考試都難過ＨＫＣＥＥ
ＨＫＣＥＥ　ｇａｒ　Ｍａｔｈｓ　ＭＣ最容易做唔晒
我最高速都只係淨１５分鐘〔成績係＝．＝錯左唔題．．．最差ｇａｒ一次〕
Ｐａｐｅｒ　Ｉ好少少～但係差唔多冇時間諗
...

我都重未試過做唔哂...
通常我都有一半時間剩...

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