Question 808035
7    	m	+	12    	n	=	-1    	.............1	
Total value								
5    	m		-3    	n	=	7    	.............2	
Eliminate	y							
multiply (1)by		1    						
Multiply (2) by		4    						
7    	m		12    	n	=	-1    		
20    	m		-12    	n	=	28    		
Add the two equations								
27    	m				=	27    		
/	27    							
m	=	1    						
plug value of			m	in (1)				
7    	m	+	12    	n	=	-1    		
7    		+	12    	n	=	-1    		
			12    	n	=	-1    		-7    
			12    	n	=	-8    		
				n	=	- 2/3