Whenever you see a log a + log b it says the same thing as log (ab). And whenever you see log a - log b it is the same as log (a/b).

So log 64 - log 128 = log (64/128) and log 32 + log 256 = log (256×32)

Now you have [log (64/128)] + [log (256×32)]

This then reduces to log [(64/128)(256×32)]

log 4096 ≈ 3.61236