For what values of x and y is the equation (x2 + y2)2 = (x2 – y2)2 + (2xy)2 true? A) all values of x, and all values of y
B) all values of x, but only positive values of y
C) only positive values of x, but all values of y
D) only positive values of x, and only positive values of y

Factor: 27a3 + 64b3
A) (3a + 4b)(9a2 + 12ab + 16b2)
B) (3a + 4b)(9a2 - 12ab + 16b2)
C) (3a - 4b)(9a2 + 12ab + 16b2)
D) (3a - 4b)(9a2 + 12ab - 16b2)

if you could please explain thank you.