中三數學...極急極急急極...

2008-01-03 2:35 am
2^x+1-2^x=2^3
x=?

x^2-2(a-b)x+a^2-ab-2b^2
x=?
幫幫手...我急要溫習
更新1:

x^2-(2a-b)x+a^2-ab-2b^2 ...咁樣呢?

更新2:

約簡呢?...sry....條題目人地比我...打錯野

更新3:

x^2-(2a-b)x+a^2-ab-2b^2 淨係Simplify佢...唔係搵X....

回答 (2)

2008-01-03 3:53 am
1.2^x+1-2^x=2^3
2^x*2-2^x=2^3
2^x(2-1)=8
2^x=8
so x=3

2008-01-02 19:54:14 補充:
第2條唔係方程或....點做
2008-01-03 2:55 am
1)(2^x)x2-2^x=2^3
2^x=2^3
x=3
2)唔係好知你條式係點,sorry!!!!!


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