數學二元方程題目Help..
回答 (2)
2011-12-09 4:22 am
✔ 最佳答案
設遊戲區的長為x 米,則闊為=(100-2x)/2
=50-x 米
x(50-x)=616
50x-x^(2)=616
x^(2)-50x+616=0
(x-28)(x-22)=0
x=28或22 (捨)
當x=28時,闊為(50-28=)22
故此,遊戲區的長和闊分別為28米和22米
參考: me o_o
2011-12-09 4:29 am
設遊樂區的長為xm,闊為ym.
2(x+y)=100......(1)
xy=616......(2)
由(1),
x+y=50
y=50-x......(3)
代(3)入(2)
x(50-x)=616
x^2-50x+616=0
x=28 or 22
代x=28入(3)
y=50-28
=22
代x=22入(3)
y=50-22
=28(rej.)------>ycannot>x
therefore,
長=28米,闊=22米.
2(x+y)=100......(1)
xy=616......(2)
由(1),
x+y=50
y=50-x......(3)
代(3)入(2)
x(50-x)=616
x^2-50x+616=0
x=28 or 22
代x=28入(3)
y=50-28
=22
代x=22入(3)
y=50-22
=28(rej.)------>ycannot>x
therefore,
長=28米,闊=22米.
參考: me
收錄日期: 2021-04-12 11:17:14
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20111208000051KK00782