If x and y are integers such that x^2=64 and y^3=64 which of the following could be true?

I. x=8

II. y= -4

III. x +y= -4A) I only

B) II only

C) I and III only

D) II and III only

E) I, II and III

*x* could be –8 or 8, but *y* can only be 4: , not 64.

**I** can therefore be true. **III** can also be true if *x* = –8 and *y* = 4.

So the answer is **C**.