智游城

标题: 找规律 [打印本页]

作者: wudihulu 时间: 2013-8-21 11:03
标题: 找规律
第一个框框右下角是3

作者: dawnsail 时间: 2013-8-21 15:55
图片太小了，看不清楚

作者: maomaobiao 时间: 2013-8-22 14:49
28

Don't ask me why

作者: wudihulu 时间: 2013-8-23 00:52

maomaobiao 发表于 2013-8-22 14:49
28

Don't ask me why

Ok, I won't ask you why, but how did you get that number? Thanks.

作者: 老陈 时间: 2013-8-23 06:06
我瞎蒙一下：28

作者: maomaobiao 时间: 2013-8-23 07:18

wudihulu 发表于 2013-8-23 02:52
Ok, I won't ask you why, but how did you get that number? Thanks.

I used preliminary linear algebra, which I suspect is not within the range of grade 7.

If you want to use the mathematics in grade 7 to solve this, I can not help.

O btw, I do not garantee the answer is correct. {:soso_e137:}

作者: 老陈 时间: 2013-8-23 07:23
I knew why. Make 3 equitions and solve them. Put into last square.

作者: maomaobiao 时间: 2013-8-23 07:32

老陈发表于 2013-8-23 09:23
I knew why. Make 3 equitions and solve them. Put into last square.

Ah, "san yuan yi ci fang cheng"

//bow grandmaster makes difficult problem easy and straight forward.

作者: wudihulu 时间: 2013-8-23 10:29
请两位高手详解，谢谢！
三元一次方程也在初一奥数范围之内。

作者: maomaobiao 时间: 2013-8-23 11:26
1A + 2B + 3C =20
3A + 4B + 2C =26
1B + 4C =19

-------------------------------

2A + 4B + 3C = ??

solve the three equations above, to get A, B, and C. Then answer ?? is 28.

作者: 老陈 时间: 2013-8-23 11:27

x+2y+3z=20.    (1)
3x+4y+2z=26. (2)
y+4z=19.          (3)
-2(3)+(1)
x-5z=  -18. (4)
-4(3)+2
3x-14z= -50.  (5)
-3(4)+(5)
Z=4
代入（4）

X=2
代入（3）
y=3

2x2+4x3+3x4=28

作者: wudihulu 时间: 2013-8-23 13:35
果然高手啊！感激加膜拜

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