若x^2+y^2+2x-8y+17=0试求（x-3y)^2-(x+3y)^2的值

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 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 若x^2+y^2+2x-8y+17=0试求（x-3y)^2-(x+3y)^2的值 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 x*x+2x-y*y+6y-8=0,x+y不等于2,求x-y的值 已知X*X+Y*Y+6X-8Y+25=0 求（Y/X)+(X/Y)-2=? 【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x^2+y^2-6x+8y+25=0 则y/x-x/y的值是 若x,y为正数,且2*x+8*y-x*y=0,求x+y的最小值 若x^2+y^2+2x-8y=-17,求y/x的值 若x^2+y^2+2x-8y=-17,求y/x的值. x'2+2x+y'2-8y+17=0,求x'y的值 x^2+2x+y^2-8y+17=0,求x^y x+2x+y-8y+17=0,求x∧y 若x²-2y+y²+8y+17=0,则x=?y=? 若x的平方-2y+y的平方+8y+17=0,则x= ,y= 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 若x+y^2-8y-6y+25=0,试求3x+4y的值xiexie!