若2x-3y=3y-4x=-5,求x,y的值

若x-y/x+y=5,求x-y/2x+2y+5x+5y/3x-3y的值 若x^5+x^4y+x^4+x+y+1=0,且3x+2y=1,求x,y的值 1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值 已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值. 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y/2x-y的值 若x、y、z满足2x+3y+z=18,4x-3y+5y=24,求x+3y的值. (1)已知x+y=6,x²-y²=5,求x-y的值（2）若x+y=3,x²+y² 已知x^3+xy^2+x+x^2y+y^3+y=0,求5x-6y/3x+4y的值. 若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值 若x+y=-5,xy=3,求x/y+y/x的值 已知3x-2y/x+y=5/3求x；y的值