2006-10-15 01:10 PM
sharon0220
再ASK 數學 (急)
今次想問 log的問題,,THZ`
麻煩大家寫埋個STEPS上黎....
解下列方程:
1) log x + log 2 =2
2) log (x-3) = log (x+8) - log 12
THZ`
2006-10-15 05:06 PM
unkle_sb
1.log x + log 2 = 2
log2x = 2
2x = 10^2
2x= 100
x =50
2. log (x-3) = log(x+8) - log 12
log(x-3) = log[(x+8)/12]
(x-3) = (x+8)/12
12x -36=x+8
11x=44
x=11