Select all of the following equation(s) that are quadratic in form. A)x4 – 6x2 – 27 = 0

B)3x4 = 2x

C)2(x + 5)4 + 2x2 + 5 = 0

D)6(2x + 4)2 = (2x + 4) + 2

E)6x4 = -x2 + 5

F)8x4 + 2x2 – 4x = 0