Answer:
First write them in positive exponent form
(16/81)¾ × [ (9/25)^3/2 ÷ (2/5)³ ]
(2⁴×¾)/ (3⁴×¾) × [ (3² × ^3/2) / (5² ×^3/2) ÷ 2³/5³)
Simplify the terms
2³/3³ × ( 3³ / 5³ ÷ 2³/5³)
Solve the terms in the bracket
2³/3³ × (3³/5³×5³/2³)
You will get
2³/3³ × 3³/2³ = 1
They will cancel each other so the answer will be 1
Hope this helps.