maths

1. 60%x50% = 60% x 50/100 = 30%
2. 50x(1-20%) = 50 x 80% = 50 x 80/100 = 40
3. 90/(1+20%) = 90/120% = 90x100/120 = 75
4. 7.5/(1-95%) = 7.5/5% = 7.5 * 100/5 =150

最後一條唔明你講乜，乜o野叫做(1=20%)？

2007-10-15 16:58:26 補充：
最後一條係咪3分之2x1.8/(1+20%)?呢條如果唔俾用計數機，俾個Form 4 計都肯9成覺得難2/3 x 1.8/(1+20%) = 2/3 x 1.8/(1.2) = 2/3 x 3/2 = 1

2007-10-16 13:42:04 補充：
7.5/(1-40%) = 7.5 / 60% = 7.5 x 100/60 = 7.5 x 5/3 = 2.5 x 5 = 12.5

60%x50% = 60/100x50/100=3000/10000=3/10


50x(1-20%) = 50x80/100=4000/100=40


90/(1+20%) = 90/(120/100)=90x(100/120)=9000/120=900/12=150/2=45


7.5/(1-95%) = 7.5/(5/100)=7.5x(100/5)=7.5x20=150


3分之2x1.8/(1=20%

60%x50% = 60/100x50/100=3000/10000=3/10

50x(1-20%) = 50x80/100=4000/100=40

90/(1+20%) = 90/(120/100)=90x(100/120)=9000/120=900/12=150/2=45

7.5/(1-95%) = 7.5/(5/100)=7.5x(100/5)=7.5x20=150

3分之2x1.8/(1=20%)
↑以上呢條數式好似有問題,(1=20%)即係咩意思

頭4條希望幫到你,第5條在下愛莫能助

2007-10-15 17:01:16 補充：
90/(1 20%) = 90/(120/100)=90x(100/120)=9000/120=900/12=150/2=75

2007-10-15 17:03:26 補充：
2/3x[1.8/(120/100)]=2/3x[1.8x(100/120)]=2/3x(180/120)=2/3x3/2=1

2007-10-15 20:29:54 補充：
---------------------------------------------------------------------7.5/(1-40%)=7.5/(60/100)=7.5x(100/60)=750/60=12.5---------------------------------------------------------------------