If x, y and r are positive integers greater than 1, and x and y are factors of r, which of the following must be the factor of r^(xy)?
I. x+y
II. y^x
III. x^2 * y^2 Choices
A) I only  B) II only  C) III only  D) I and II  E) II and III
given that p and q are factors of r.   so we can picture it this way r=x*y*n (n-some another factor of r)   so, r^xy= (x*y*n)^xy   I. x+y .since the question is MUST BE TRUE, we eleminate this option   II. (x*y*n)^xy / y^x= integer YII and IIIS!   III.(x*y*n)^xy/ x^2 * y^2 YII and IIIs, since we are said that integer x&gt;1 and integer y&gt;1
<result>E</result>
If x, y and r are positive integers greater than 1, and x and y are factors of r, which of the following must be the factor of r^(xy)?
I. x+y
II. y^x
III. x^2 * y^2