x/2+y/3=13/2,（1）x/3-y/4=3/2,(2）（1）*3 变3x+2y=39,(3)
(2)*2变4x-3y=18 (4)
(3)+(4)
X=9,代入（3）得Y=6 解得 X=9,Y=6���˰�2/3x��3/4=18 2-6/13��9/39-2/3 ����2����֪��������һ�����ǰ�ʲô����һ��Ӵ������1��2-6/13*26/9-2/3 =2-4/3-2/3 =2-(4/3+2/3) =2-2 =0(2)1/4*39+3/4*25+3/4*14 =1/4*39+(3/4*25+3/4*14) =1/4*39+3/4*(25+14) =1/4*39+3/4*39 =39*(1/4+3/4) =39*1 =39�� ��1��2-6/13*26/9-2/3 =2-4/3-2/3 =2-(4/3+2/3) =2-2 =0����