若|x-2|+（x+2y)^2=0,则式子4x^3y^5的值为______

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 若x+y=1,x不等于0则x+(2xy+y^2)/x/(x+y)/x= 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 若|x+y-1|+（x-y-2)²=0,求代数式（x+2y)(x-2y）-（2x-y)(-y-2x)的值. 若3x-5y=0,则x+y/x=（）,x-y/y=（）,2x-3y/2x+3y=( ) 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 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2x=3y,则(x*x+y*y)/x*x=? 求y=(x^2)+2x(x≥0) y=-x+2x(x 已知x>0,Y>0,如何证x^2/y+y^2/x>=x+y 若f(x+y,y/x)=x^2-y^2,则F(X,Y)= 变量x,y满足x-2y=0,x 若2x-5y=0,则y：x x*x+2x+y*y-4y+5=0 x= y= 设Z=X+Y,其中X,Y满足X+2Y>=0,X-Y 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 若x*x+y*y=x+y-1/2,求x,y的值如题