2004x+2005y=2006 (1)2005x+2004y=2006 (2)(1)+(2)4009x+4009y=4012x+y=4012/4009 (3)(2)-(1)x-y=0 (4)(3)+(4)2x=4012/4009x=2006/4009y=x=2006/4009
