PSAT math questions ?

Question

if k, n and y are positive numbers satisfying x^(-4/3)=k^(-2) and y^(4/3)=n^2 , what is (xy)^(-2/3) in term of n and k

Answer 1

x^(-4/3) = 1/(x^(4/3)) = 1/k² or x^(4/3) = k²

so (xy)^(4/3) = (kn)² or

(xy)^(2/3) = ±(kn)

or

1/[(xy)^(2/3)] = ±1/(kn) = (xy)^(-2/3)

Answer 2

x^(-2/3) = k^(-1)

y^(-2/3)= n^(-1)

that mean

(xy)^(-2/3) = k^(-1)*n^(-1)

Answer 3

hi

( x^(-2/3))^2 =k^(-2)

(y^(2/3))^2 = n^2

x(-2/3)=k^(-1)

y(-2/3)=n^(-1)

(xy)^(-2/3) =( kn)^(-1)=1/kn

Answer 4

n^2(k-2)=(kn)-2/2