Question 714909
x		-	y	=	10	.............1	
Total value								
2	x	+		y	=	2	.............2	

Since the co-efficients of y are equal and have opposite signs, we choose to eliminate y
Eliminate	y							
1	x		-1	y	=	10		
2	x	+	1	y	=	2		
Add the two equations								
3	x				=	12		
/	3							
x	=	4      						
plug value of			x	in (1)				
1	x		-1	y	=	10		
4			-1	y	=	10		
			-1	y	=	10		-4
			-1	y	=	6		
				y	=	-6