Maths唔識抵死題(QUICK!!!!!!!!!!!!!)

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圖片參考：http://img254.imageshack.us/img254/4965/64851481.png


2010-11-27 21:41:12 補充：
http://img254.imageshack.us/img254/4965/64851481.png

2010-11-28 12:13:17 補充：
(a) 4^x=256
xlog4=log256
x=log256/log 4=4

(b) 2^x=8
xlog2=log8
x=log8/log 2=3

can u try to do these sums by using logarithm???

i know how to solve by using log but i can't get the answer.

do it and 2 marks will be added.!!!!!!!!!!!

2010-11-28 12:34:25 補充：
why?

4^x=256 ?????
2^x=8????

where is the 320 and 4^x-1?????
6*2^x-1????????????????????

can u show more workings for both a&b????
add 2 fun!!!!