y4 - 256 = (y2 - 16)(y2 + 16) = (y - 4)(y + 4)(y2 + 16)
(y - 4)(y + 4)(y^2 + 16)
(2x - y2)(4x2 + 2xy2 + y4)
The GCF is y4
(y^2 + 8)(y^2 + 2)
y4
x=y4 /2
4x-y4 what = 0
The simplest equation would be y4 = 0
The remainder is not zero so y-3 is not a factor of y^4+2y^2-4
(x2 + y2)(x + y)(x - y) = x4 - y4.
4z2