中一數學，，，，好難做

no.1:
呀恩同呀瑩2個攤fun$3000,如果呀恩得的比呀瑩有的2 over3(2/3)+200$,2個會有幾$??

A. Let呀恩 gets $a, 呀瑩 gets $y.
a+y = 3000
a-200 = y(2/3)
y = [3(a-200)]/2
So,
a+[3(a-200)]/2 = 3000
2a+3a-600 = 6000
a = 6600/5
a = 1320
So, y = 3000-1320
= 1680
So, 呀恩 gets $1320, 呀瑩gets $1680.

no.2:
1個computer同1個keyboard=$6300,學校buy左20部computer同2個keyboard.1部電腦的$=??

A. Total amount of $ of 20部computer同2個keyboard is missing…

2009-11-17 18:41:26 補充：
No.2:
1個computer同1個keyboard=$6300,學校buy左20部computer同2個keyboard,$99000,
1部電腦的$=??

A. Let 1部電腦 cost $c, 1個keyboard cost $k.
c+k = 6300
k = 6300-c
20c+2k = 99000
So,
20c+2(6300-c) = 99000
18c = 86400
c = 4800
So, 1部電腦 cost $4800.

第一,二題唔明你寫既意思,請在補充寫番清楚D...
再答

題目好像漏了一點東西...