Math
posted by Sabrina .
Are you allowed to do this
2log(x1) =log(x+1)
2 (x1)=(x+1)
x=3
Please help :)


Some mathteacher published a book some time ago listing all the silly solutions that students had produced.
It actually had it this way
2log(x1) =log(x+1)
(2log(x1))/log = (log(x+1))/log , then the log/log canceled
2(x1) = (x+1)
2x  2 = x+1
x = 3, which by sheer coincidence is the right answer. 
My teacher showed us this one:
64/16
= (6)4/1(6) [cancel the 6]
= 4/1
= 4
gets the right answer, but the wrong way.
Respond to this Question
Similar Questions

LOGARITHMS
HI THE QUESTION STATES THAT ONE SHOULD CALCULATE THE LOGS WITHOUT THE USE OF A CALCULATOR...OKAY MY PROBLEM IS THIS... 2 3 2log 8 + 2log 8 what should i do? 
mathematics logs
which three statements are true? a) if x= 10^4 then log 10 = 4 b)if x= 2^8 then log 2x = 8 c) log2 2= 4 d) if x= 3 then log10 3=x e) log 10 2562log 10 a/log 10 b f)log 10 (ab)= log 10 a/log 10 b g) the gradient of the graph of 
maths
which three statements are true? a) if x= 10^4 then log 10 = 4 b)if x= 2^8 then log 2x = 8 c) log2 2= 4 d) if x= 3 then log10 3=x e) log 10 2562log 10 a/log 10 b f)log 10 (ab)= log 10 a/log 10 b g) the gradient of the graph of 
Logarithms
Hi, Can anyone tell me if the following are correct please: If x = 10y (where x > 0), then log10 x = y if a and b are positive numbers, then, 2 log 10 a / b = 2log 10 a  2 log 10 b and lastly if a and b are positive numbers, then, … 
Math
Express as a single logarithm. 1/2log(subscript)3 144log(subscript)3 4+2log(subscript)3 3 Please Help!I just can't seem to get the correct answer when I do it. 
Precalculus
What am I doing wrong? I keep getting 48 and its wrong... Solve 2log(x)log(4)=3log(4) 2log(x)log(4) log(x/4)=3log4 log(x/4)=log12 x=48 
Math
solve log(7x3)+2log(5)=2+log(x+3) I've attempted to do this question and I ended up with log(73)+log(5^2)log(x+3)=2 but I don't what to do next or whether I did something wrong. 
Math
Are all statements that are true. (a) log(A)/log(B)=In(A)/In(B) (b) In log[b](N), the exponent is N. (c)If 2log[3](81)=8, then log[3](6.561)=8 (d)log[b](N) negative when N is negative. (e)In(x/2)=In(x)/2 
Math
Are all statements that are true. (a) log(A)/log(B)=In(A)/In(B) (b) In log[b](N), the exponent is N. (c)If 2log[3](81)=8, then log[3](6.561)=8 (d)log[b](N) negative when N is negative. (e)In(x/2)=In(x)/2 
math
Q1:solve log(5)xlog(25)(x+10) = 0.5 Q2:If 2log(a)x=1+log(a) (7x10a) ,find x in terms of a. Q3:Find x for which 27x3^lgx = 9^1+lg(x20) Q4:Find x in terms of a and c ,given that log(√ a)(1/x)+log(a)x +log(a^2) x +log (a^4)x=c