已知(x+y):y=8:3,求2x+5y/3x-y和x^2-xy/y^2+3xy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:3x-5y=0,求x/y,x-y/y,x-y/x 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 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|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知(3x+1)(3x-3)-3x+2)^2=-7,(y+7)(y-7)-y(y-7)=0,求8y^2-5y(-y+3x)+4y(-4y-5/2x)的值 已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 已知7Y=X-3,8Y=X+5 求X和Y 已知x-2y=2,求4x-y-8分之3x+y-6 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