Could you tell us what you came up with so far?
But for the first part, I don't understand where the c comes from...
Okay, for the next one, I'm not sure if this is the right method, but it's quite long.
[From here, we know that ]
Divide by ln(2)
We consider only the centre and right parts now and used what we found a little earlier to remove the natural logs.
Can you continue now?