若2x-y=8,则6-2x+y=?

若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 若x^2+y^2-6x+8y+25=0 则y/x-x/y的值是 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 若f(x+y,y/x)=x^2-y^2,则F(X,Y)= 若x-y不等于0,2x-3y=0,则分式(10x-11y)/(x-y)的值是（）?(10x-11y)/(x-y) =[(8x-8y)+(2x-3y)]/(x-y) =8为什么8X-8Y=8？(10x-11y)/(x-y)=[(8x-8y)+(2x-3y)]/(x-y)=8+(2x-3y)]/(x-y)=8+0=8 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? x*x+2x-y*y+6y-8=0,x+y不等于2,求x-y的值 若2X+3Y-1=Y-X-8=X+6则2X+Y= 若2X+3y-1=y-x-8=x+6,则2x-y=? 若X+6=Y-X-8=2X-3Y-1,则3X-Y=? 若x+6=y+x-8=2x-3y-1,则x-y= 若X+6=Y-X-8=2X-3Y-1,则3X-Y=? 【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y) 若2x=3y,则(x*x+y*y)/x*x=? 若5x+3y=3x+4y=x+2y+6,则x+y=___ 若X+Y=8,(X-Y)^2=4,则X^2+Y^2= 若【x+y=5,2x+y=8】,则x+2y=