25log81 × 27log1/64 × 8log1/125

^ tanda pangkat
(5²)log 3⁴ × (3³)log 8^-2 × 8log 5^-3
= (4/2).5log 3 × (-2/3).³log 8 × (-3).8log 5
= (4/2)(-2/3)(-3) . 5log 3 × ³log 8 × 8log 5
= 4 . 5log 5
= 4(1)
= 4