5X+Y=2 (1)X-3Y=4 (2)解:由(1)得 Y=2-5X (3) 将(3)代入(2),得 X-6+15X=4 16X=10 X=5/8 (4) 将(4)代入)(3),得 Y=2-25/8 Y=-9/8所以:X=5/8,Y=-9/8