已知3x=5/2,3y=25,求3y-x的值

已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值 已知3x-2y/x+y=5/3求x；y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-y|+|x+y|=0,求x-y除以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=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的值 已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值. 已知X/Y=5/3,求X/(X+Y)+X/(X-Y)-Y*2/(X*2-Y*2)的值. 初二数学已知(x-y):y=2:3,求(2x+5y):(3x-y)的值 已知x-3y=0(y≠0)求2x+5y/3x-2y的值 已知（2x+3y+5)^2+!3x+2y-25!=0,求x,y的值