Step-by-step explanation:
64^1/3 (64^1/3 - 16^2/3)
= 4^(3×1/3) {4^(3×1/3) - 4^(2×2/3)}
= 4(4 - 4^4/3)
= 16 - 4^(1+4/3)
= 16 - 4^(7/3)
= -9.3984
