Question 566470
2	x	+	1	y	=	5	.............1			
1	y	=	1		-2	x	---------2			
/	1	=								
	y	=	1		-2	x				
Substitute y in 		(1)								
2	x	+	1	(	1		-2	x	)	=
2	x	+	1	+	-2	x	=	5		
2	x		-2	x	=	5	-1			
0	x	=	4							
/	0									
x=	undefined

So the system has no solution. The lines are parallel