Treat each component separately and break it down...Note that when a number has a power that is a fraction, the numerator acts as a power and the denominator acts as a root(16)^1/4 = 2. Okay, brilliant!So what about (16)^3/4? If it makes it easier, this can be rewritten as [(16)^1/4]^3[(16)^1/4]^3 = [2]^3 = 8. Well done! Why would it be relevant to work out (81)^3/4? How can you show that, by answering this, you can find the answer to (16/81)^3/4?