1.	Solve x4 - 5x2 + 4 = 0.
		A.	-1, 1	B.	-1, 1, -2i, 2i
		C.	1, 2	D.	-1, 1, -2, 2
		Hint
	2.	Solve .
		A.	4	B.	16
		C.	4, 16	D.	-4, 2
		Hint
	3.	Write the expression in quadratic form.
		A.		B.
		C.		D.
		Hint
	4.	Which expression cannot be written in quadratic form?
		A.		B.
		C.		D.
		Hint
	5.	Solve
		A.		B.	1, 11.31
		C.		D.	1, 1.22
		Hint