²log 18 - ²log 8√2 + ²log 1/27 - ²log ⅓

²log 18 - ²log 8√2 + ²log 1/27 - ²log ⅓
= ²log(18.1/27)/(8√2.1/3)
= ²log(2/3)/(8√2/3)
= ²log(2/3).(3/8√2)
= ²log(1/4√2)
= ²log1/2^5/2
= ²log2^-5/2
= -5/2 . ²log2
= -5/2