<p>Help please.</p>
<p>x^-4/3 = 1/ x^4/3 and k-2 = 1/k^2 which tells us x^4/3 = k^2. Remember that taking the square root is like multiplying the exponents by ½. If we simplify the equation by taking the square root of both terms we find x^2/3 = k. If we do the same to y^4/3 and n^2 we get that y^2/3 = n.</p>
<p>So (xy)^-2/3 = 1/(x^2/3*y^2/3) and that means this equals 1/nk.</p>
<p>The answer is A.</p>
<p>You isolate X and Y but Multiplying K^-2 and N^2 by 1/-4/3 and 1/ 4/3 to get k^6/4 and n^6/4, then you apply -2/3 to both k^6/4 and n^6/4 to get K^-12/12 and N^12/12 which is KN. But since 1 of them is negative, you take the reciprocal to convert it to positive, so its 1/KN</p>
<p>Sorry if that confused you! im bad at explaining =(</p>