代數題唔識計......請幫下我.......top urgent !!!!!

設全場共有x隻家禽

因為鴨子佔60%, 雞則佔40%, 而鴨比雞多4隻:

60%x=40%x+4

0.6x=0.4x+4

0.6x-0.4x=4

0.2x=4

x=4/0.2

x=20

∴全場共有20隻家禽


2007-01-16 22:11:56 補充：
順便驗證埋：鴨有20*60%=20*0.6=12隻雞有20*40%=20*0.4=8隻12-8=4(隻)即係鴨比雞多4隻

設全場共有x隻家禽.
60%x = 40%x + 4
0.6x = 0.4x + 4
0.2x = 4
x = 20
因此全場共有20隻家禽.

鴨子數目 = 20(0.6) = 12隻
雞的數目 = 20(0.4) = 8隻

let the number of fowls in the farm be x
then 60%x are ducks, 40%x are chickens

0.6x-0.4x=4
0.2x =4
x =20

so, there are 20 fowls in the farm.

60+4+X=100
X=100-60-4
X=36

全場共有20隻家禽