(x+y)^2+x^2=6 (1)7y^2+xy=6 (2)(1)-(2) 2x^2+xy-6y^2=0(2x-3y)(x+2y)=0x=3/2y (3)x=-2y (4)把(2)和(3)、（2）和(4)联立方程组解得x=3根号51 x=-3根号51 x=2根号30/5 x=-2根号30/5 y=2根号51 y=-2根号51 y=-根号30/5...