1.	A graph of a system of three linear equations in three variables is shown below. How many solutions does the system have?
		A.	0	B.	1
		C.	2	D.	infinite number
		Hint
	2.	Solve the system 4y – 6x + 8z = 13, 10y – 15x + 20z = 6, y – 5x + 2z = 5.
		A.	(-3, 1, 7)	B.	infinite solutions
		C.		D.	no solution
		Hint
	3.	At a firm, there are three workers that are supposed to work a combined 110 hours per week. Worker 1 is supposed to work 5 hours more than worker 2, and worker 2 is supposed to work 15 hours more than worker 3. How long should each one work?
		A.	worker 1: 45worker 2: 35worker 3: 30	B.	worker 1: 45worker 2: 40worker 3: 25
		C.	worker 1: 40worker 2: 45worker 3: 25	D.	worker 1: 42.5worker 2: 37.5worker 3: 30
		Hint
	4.	At a firm, there are three workers that are supposed to work a combined 110 hours per week. Worker 1 gets paid $10 per hour, worker 2 gets paid $12 per hour, and worker 3 gets paid $14 per hour. If the company wants their total income to be $1268, how many hours should each one work if worker 3 and worker 2 work for the same amount of hours?
		A.	worker 1: 54worker 2: 28worker 3: 28	B.	worker 1: 44worker 2: 33worker 3: 33
		C.	worker 1: 40worker 2: 35worker 3: 35	D.	worker 1: 14worker 2: 48worker 3: 48
		Hint
	5.	What is true about a system of equations in three variables that has 1 solution?
		A.	planes intersect in one line	B.	planes have no points in common
		C.	planes intersect in the same plane	D.	planes intersect in one point
		Hint