2x^2+9y^2+8x+12y+12=0,2x-3y-?

3y=2x y/3=x/2 12/x=9/y y/x=?y/x=?x/y=? 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, x-2y=9 x+y+z=7 2x-3y=12 9y=3x-(x-1),4(x+y)-(2x+4)=8y 3x-2y=9 x-3y=2 x+y=5 x+2y=3 y=x 2x+y=8 已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y除以2x-y 已知2x-y/x+3y=2,求代数式4x-2y/x+3y减4x+12y/2x-y的值 ①x+y+z=6 3x-y+2z=12 x-y-3z=-4 ②x+y-z=2 4x-2y+3y+8=0 x+3y-2z- 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)