Question 1027945
By elimination method

3	x	+	2	y	+	1	z	=	8			--------------				1
2	x	+	-3	y		2	z	=	-16			--------------				2
1	x	+	4	y	+		-1	z	20			--------------				3
																
consider equation 1 &2				Eliminate	y											
Multiply 1 by		3					-5									
Multiply 2 by		2					4									
we get																
9	x		+	6	y	+	3	z	=	24						
4	x		+	-6	y	+	4	z	=	-32						
Add the two																
13	x		+	0	y	+	7	z	=	-8	-------------				4	
consider equation 2 & 3				Eliminate	y											
Multiply 2 by				4												
Multiply 3 by				3												
we get																
8	x	+	-12	y	+	8	z	=	-64							
3	x	+	12	y	+	-3	z	=	60							
Add the two																
11	x	+	0	y	+	5	z	=	-4	-------------5				5		
Consider (4) & (5)			Eliminate	x												
Multiply 4 by				-11												
Multiply (5) by				13												
we get																
-143	x	+	-77	z	=	88										
143	x	+	65	z	=	-52										
Add the two																
0	x	+	-12	z	=	36										
/	-12															
z	=	-3														
																
																
																
																
																
Plug the value of			z	in		(5)										
11	x	+	5	z	=	-4										
11	x	=	11													
x	=	1														
x=1, z=-3

Plug the values to get y

y=4