20x(1+x%)=x
then x=? (比埋步驟,plx!)
20x(1-%)=y
then y=? also比埋步驟,plz!!)
plz help,thx!!!!!!!!
F.1 MATHS 題.20 marks!急
2010-07-21 10:47 pm
回答 (3)
2010-07-22 12:30 am
✔ 最佳答案
20x(1+x%)=x1+x%=x/20
100/100+x/100=x/20
100+x=100x/20=5x
100=5x-x=4x
x=25
20x(1-y%)=y
1-y%=y/20
100/100-y/100=y/20
100-y=100y/20=5y
100=6y
y=50/3=16.67
參考: 自己
2010-07-21 11:47 pm
1) 20x(1+x%)=x
20+20x%=x
20x%-x=-20
20x/100-x=-20
x/5-x=-20
x-5x=-100
-4x=-100
x=25
2) 20x(1-y%)=y
20-20y%=y
-20y%-y=-20
-20y/100-y=-20
-y/5-y=-20
-y-5y=-100
-6y=-100
-y=-16/2/3
y=16/2/3
俾40點我
20+20x%=x
20x%-x=-20
20x/100-x=-20
x/5-x=-20
x-5x=-100
-4x=-100
x=25
2) 20x(1-y%)=y
20-20y%=y
-20y%-y=-20
-20y/100-y=-20
-y/5-y=-20
-y-5y=-100
-6y=-100
-y=-16/2/3
y=16/2/3
俾40點我
參考: me
2010-07-21 10:51 pm
20x(1+x%)=x
20+20%x..=x
20%x-x.....=-20
-80%x.......=-20
x..............=25
________________
20x(1-y%)=y
20-20%y..=y
-120%y....=-20
y.............=50/3
20+20%x..=x
20%x-x.....=-20
-80%x.......=-20
x..............=25
________________
20x(1-y%)=y
20-20%y..=y
-120%y....=-20
y.............=50/3
收錄日期: 2021-04-15 17:36:49
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100721000051KK00878