Hello Guys i have a logarithme lesson, and our teacher gave us some exercices but he didn't explain all the lesson.

compare without a calculater:

Ln7 and ln2 + ln 3

For me: 7>3+5 --> Ln7>ln5

3+ln (radical)e and 4 ? well i don't know how to compare it.

Resolve this:

lnx =1 ; ln 2x=0 ; lnx=-1 ; lnx=3 ( what i have to do here)??

ln(x-3)=ln(x+7)-ln(x+1)??

ln(x^2-2x-3) = ln(x+7)

the teacher told us to do them and he gave us this

ln(ab) = ln (a) +ln(b) but i can't do them....

Please help me i have many exercices like these and when somebody could help me i guess i can solve the others ones

Many thanks in advance