Please help with these 2 questions!
The following system is solved by substitution. Which expression is substituted for z in the second and third equations?

x + 4y + z = -10
3x - 3y + 6z = -21
x + 2y + 2z = -10

x + 4y - 10
-x + 4y - 10
-x - 4y - 10
x - 4y - 10
3. Solve the following system of equations.

x + 3y + 2z = -16
2x - y + 2z = -15
2x - 2y - z = 1

(-3, -1, -5)
(-3, 5, -2)
(2, -4, -3)
(4, 4, -1)

Question

Please help with these 2 questions! 
The following system is solved by substitution. Which expression is substituted for z in the second and third equations?

x + 4y + z = -10
3x - 3y + 6z = -21
x + 2y + 2z = -10
 	
	x + 4y - 10
	-x + 4y - 10
	-x - 4y - 10
	x - 4y - 10
3. 	Solve the following system of equations.

x + 3y + 2z = -16
2x - y + 2z = -15
2x - 2y - z = 1
 	
	(-3, -1, -5)
	(-3, 5, -2)
	(2, -4, -3)
	(4, 4, -1)

anonymous · Answer

What school do you go to? CA?

anonymous · Answer

Online
Brainhoney

anonymous · Answer

Which online school? I might be able to help you

anonymous · Answer

GCS Brainhoney is the name of it, I live in NC