How do you do this math problem?

[gnuel3]

log (x-1) = log (x-2) - log (x+2), solve for x..

I'm stuck..

 

[AntMan530]

just punch it in your ti-92 man

 

[gnuel3]

Dont have one. :X

 

[dighn]

log(a)-log(b) = log(a/b)

 

[gnuel3]

Yeah, i know that part.. What do you do after that?

 

[ArmenK]

log (x-1) = log (x-2) - log (x+2)
log (x-1) = log[ (x-2)/(x+2) ]
x-1 = (x-2)/(x+2)

solve

 

[VIAN]

aaaah, nevermind.

 

[gnuel3]

Oh yeah! The logs cancel..forgot that...heh


Thanks alot!

 

[ArmenK]

Originally posted by: gnuel3
Oh yeah! The logs cancel..forgot that...heh


Thanks alot!

the logs dont cancel, you do e^ to both sides

for example, you couldnt cancel the logs from log (x-1) = log (x-2) - log (x+2) directly

 

[gnuel3]

Oh...Hm...oooohhh! I see it now, heh.

Thanks, heh!

 

[Dissipate]

Originally posted by: ArmenK

Originally posted by: gnuel3
Oh yeah! The logs cancel..forgot that...heh


Thanks alot!

the logs dont cancel, you do e^ to both sides

for example, you couldnt cancel the logs from log (x-1) = log (x-2) - log (x+2) directly

No, e is only if it is natural log or ln. He is talking about log and furthermore he never indicated the base of the log. I assume it is base 10.

 

[ArmenK]

Originally posted by: Dissipate

Originally posted by: ArmenK

Originally posted by: gnuel3
Oh yeah! The logs cancel..forgot that...heh


Thanks alot!

the logs dont cancel, you do e^ to both sides

for example, you couldnt cancel the logs from log (x-1) = log (x-2) - log (x+2) directly

No, e is only if it is natural log or ln. He is talking about log and furthermore he never indicated the base of the log. I assume it is base 10.

When you get to college, log = ln

 

[Dissipate]

Originally posted by: ArmenK

Originally posted by: Dissipate

Originally posted by: ArmenK

Originally posted by: gnuel3
Oh yeah! The logs cancel..forgot that...heh


Thanks alot!

the logs dont cancel, you do e^ to both sides

for example, you couldnt cancel the logs from log (x-1) = log (x-2) - log (x+2) directly

No, e is only if it is natural log or ln. He is talking about log and furthermore he never indicated the base of the log. I assume it is base 10.

When you get to college, log = ln

Huh? Not in my college. 99% of the time I don't mess with log bases other than e but I have never seen a problem where ln == log.

 

[BaboonGuy]

it's a quadratic formula problem in disguise