已知2x+y=3,x-2y=5,求2x^2-3xy-2y^2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|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 已知2y-x=-3,求[4y(2x-y)-2x(2x-y)]/(2x-y 已知2x-y=-3,求代数式5(x-3y)-2(x-7y) 已知5|x+y-3|+(x-2y)²=5,求x+y的值 已知3x-2y/x+y=5/3求x；y的值 已知x+y/3x-2y=5/3求x；y的值 已知x,y>0 2x+y+3=xy 求5x+4y最小值 已知7x+5y/2y-x=3/2,且x≠0,求X/x-4y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 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-2y=2016,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除以8x的值 已知x-2y=2012,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]/(8x)) 已知x-2y=2010,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷8x的值 已知:x-2y=2009,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除以8x 的值