Okay so I am taking calculus 1 and thought I fully understood how to find the domain of functions until I saw one with a natural log on the top.

f(x)= [ln(12-2x)]/[sqrt(x+5)-3]

so far I have deduced that x can not equal -6 because a square root cant be a negative and that x can not equal 4 because the square root of 9 would be 3 and would give us a 0 on the bottom which we cant allow. However the entire top section has me puzzled. Can anyone please explain how to work with the top end of this function.