Question 876837
2      	x	+	3      	y	+	4      	z	=	20      			--------------				1
1      	x	+	1      	y		2      	z	=	9      			--------------				2
3      	x	+	2      	y	+	1      	z	=	10      			--------------				3
																
consider equation 1 &2				Eliminate	y											
Multiply 1 by		-1      					-5      									
Multiply 2 by		3      					4      									
we get																
-2      	x		+	-3      	y	+	-4      	z	=	-20						
3      	x		+	3      	y	+	6      	z	=	27						
Add the two																
1      	x		+	0      	y	+	2      	z	=	7	-------------				4	
consider equation 2 & 3				Eliminate	y											
Multiply 2 by				-2      												
Multiply 3 by				1      												
we get																
-2      	x	+	-2      	y	+	-4      	z	=	-18      							
3      	x	+	2      	y	+	1      	z	=	10      							
Add the two																
1      	x	+	0      	y	+	-3      	z	=	-8      	-------------5				5		
Consider (4) & (5)			Eliminate	x												
Multiply 4 by				-1      												
Multiply (5) by				1      												
we get																
-1      	x	+	-2      	z	=	-7      										
1      	x	+	-3      	z	=	-8      										
Add the two																
0      	x	+	-5      	z	=	-15      										
/	-5      															
z	=	3      														
1      	x	+	-3      	z=	-8      											
1      	x	+	-9      	=	-8      											
			x	=	1      											
Plug x & z in eq (1)																
2      	x	+	3      	y	+	4      	z	=	20      			--------------				1
	2      	+	3      	y	+	12      		=	20      							
			3      	y				=	6      							
				y	=				2      							
	x=	1      	y=	2      	z=	3