Question 476435
4	x	+	1	y	=	15	.............1	
2	x	+	5	y	=	21	.............2	
Eliminate y								
multiply (1)by 		-5						
Multiply (2) by		1						
-20	x		-5	y	=	-75		
2	x	+	5	y	=	21		
Add the two equations								
-18	x				=	-54		
/	-18							
x	=	3    			
plug value of 			x	in (1)				
4	x	+	1	y	=	15		
12		+	1	y	=	15		
			1	y	=	15		-12
			1	y	=	3		
				y	=	3