1.	Which equation is in quadratic form?
		A.	3x3 + 3x + 3 = 0	B.
		C.	x4 - x2 + x - 1 = 0	D.
		Hint
	2.	Solve y4 - 18y2 + 81 = 0.
		A.	3, 3i	B.	-3, 3
		C.	-3, 3, -3i, 3i	D.	3
		Hint
	3.	Solve .
		A.	4	B.	4, 16
		C.	-4, 2	D.	16
		Hint
	4.	Solve x4 – 625 = 0
		A.		B.
		C.	5, 5i	D.
		Hint
	5.	Which expression cannot be written in quadratic form?
		A.		B.
		C.		D.
		Hint