put this in simplest form?

64) (x^2/x-11)^1/3

we can simplify this by doing the following:

(x^2)^1/3 / (x-11)^1/3

x^(2/3) / (x-11)^(1/3).

 

66) (x^-2/3/y^-1/3)^15

Since we have negative exponents, we can change their positions as follows:

[y^(1/3)/x^(2/3)]^15

Now, we can further simplify by doing:

[y^(1/3)^15] / [x^(2/3)^15]

y^5 / x^30/3

y^5 / x^10

$${\frac{{{\mathtt{y}}}^{{\mathtt{5}}}}{{{\mathtt{x}}}^{{\mathtt{10}}}}}$$.