若x^2+y^2=10,则x+y的取值范围是多少（理由）

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+2y分之x-y=3,则代数式x+2y分之2（x-y)-3(x-y)分之x+2y的值为 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 若x*x+y*y=x+y-1/2,求x,y的值如题 x,y 满足x(x-2)-y(y-6)=-10,求x,y的值 若f(x+y,y/x)=x^2-y^2,则F(X,Y)= 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 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-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 已知x-y-3绝对值+(2x+2y+10)的平方=0,则(x+y)(x-Y)= 若x.y满足x^2+4x+y^2-10y+29=0.求x+y的值 若x^2+y^2-10x-6y+34=0,求（x-y)/(x+y)的值 若x^2+y^2-6x+8y+25=0 则y/x-x/y的值是 若X+Y=2,则约分|X^2-Y^2|/X-Y的结果. 若|x+y+1|+(x-2y)的平方=0,则x+2y=? 若2x-y/x+y=2/3,则y/x的值为( ) 若正实数x.y满足x+y=xy,则x+2y的最小值 若分式x-y/2x-y =-1.则x与y的关系是