# Math Help - Log Help

1. ## Log Help

Hi guys I have a few questions that I am totally lost on.

1) Write as a single loagrithm: 4lnx - 2(lnx^3 + 4lnx)

2) Solve: 2^x = 3^(x+3)

3) Solve: log(x^2 -1) = 2 + log (x+1)

2. Hello,

Remember that $\ln(a^b)=b \ln(a)$

So how would you transform $\ln(x^3)$ in the first one ?

For the second one, this is the same : compose each side with logarithm.

For the third one, note that x²-1=(x-1)(x+1)

Then remember that $\ln(ab)=\ln(a)+\ln(b)$

3. so for the first one would it go to:

4lnx - 2(3lnx + 4lnx)

and if so would it then get distributed to 4lnx - 6lnx + 8lnx?

Sorry I'm really bad at this!!

4. Please do not double post antz

5. Originally Posted by antz215
so for the first one would it go to:

4lnx - 2(3lnx + 4lnx)

and if so would it then get distributed to 4lnx - 6lnx + 8lnx?

Sorry I'm really bad at this!!
no, it is 4ln(x) - 6ln(x) - 8ln(x)

6. Originally Posted by antz215
so for the first one would it go to:

4lnx - 2(3lnx + 4lnx)

and if so would it then get distributed to 4lnx - 6lnx + 8lnx?

Sorry I'm really bad at this!!
This is nearly it

7. Originally Posted by Jhevon
Please do not double post antz
Sorry! I wont do that again. Thank you both for your help!