²log√8+²log√2-²log16

²log8^½+²log2^½-2log2⁴
²log2^3/2+²log2^½-²log2⁴
3/2+1/2-4=-2

²log√8+²log√2-²log16=²log(√8x√2:16)
=²log(√16:16)
=²log(4:16)
=²log 1/4
= ²log 2-²
= -2 ² log2
= -2 . 1
=-2