數學文字題
2007-01-01 6:30 am
A wire 40 cm is bent to from two square .If the sure of their area is 52 cm^2 ,find the lenght of the sides of the two squares.
回答 (2)
2007-01-01 6:57 am
✔ 最佳答案
4x + 4y = 40......(1)x^2 + y^2 = 52......(2)
from(1)
y=10-x.....(3)
sub(3)to(2)
x^2+(10-x)^2=52
x^2+100-20x+x^2=52
2x^2-20x+100=52
x^2-10x+24=0
(x-4)(x-6)=0
x=4or6
y=10-4or6
y=6or4
2007-01-01 6:36 am
4x + 4y = 40......(1)
x^2 + y^2 = 52......(2)
2006-12-31 22:36:55 補充：
From (1)X = 10 - y......(3)
2006-12-31 22:39:24 補充：
sub. (3) into (2)(10 - y)^2 y^2 = 52100 - 20y y^2 y^2 =522y^2 -20y = -48y^2 - 10y = -24............
x^2 + y^2 = 52......(2)
2006-12-31 22:36:55 補充：
From (1)X = 10 - y......(3)
2006-12-31 22:39:24 補充：
sub. (3) into (2)(10 - y)^2 y^2 = 52100 - 20y y^2 y^2 =522y^2 -20y = -48y^2 - 10y = -24............
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https://hk.answers.yahoo.com/question/index?qid=20061231000051KK04862