Question 550717
10	x	+	5	y	=	52.5	.............1		
30	x		-7	y	=	80.5	.............2		
Eliminate y									
multiply (1)by 		7							
Multiply (2) by		5							
70	x		35	y	=	367.5			
150	x		-35	y	=	402.5			
Add the two equations									
220	x				=	770			
/	220								
x	=	3.50						
plug value of 			x	in (1)					
10	x	+	5	y	=	52.5			
35		+	5	y	=	52.5			
			5	y	=	52.5		-35	
			5	y	=	17.5			
				y	=	3.50