x>=0,y>=0,x+3y=9则x^2y的最大值为

（x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 若3x-5y=0,则x+y/x=（）,x-y/y=（）,2x-3y/2x+3y=( ) 已知x*x+4x+y*y-2y+5=0,则x*x+y*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 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 已知|x+y-3|+(x-y)2=0则 已知x,y为实数,根号3x+4 +y^2-6Y+9=0则x+y=? 先化简,再求值 [2/3x - 2/x+y（x+y/3x -x-y）]*x/x-y,其中5x+3y=0 若x,y满足|2x-y-3|+|3x+2y+1|=0,则x= y= 先化简,再求值:[3x-2/x+y(x+y/3x-x-y)]/(x-y/x),其中5x+3y=0 若线段x ,y 满足[2x-3y]*[3x+2y]=0 则x/y=? 若x,y满足|x-y+1|+(x+y+3)^2=0则x^2-y^2= 已知x-y-3绝对值+(2x+2y+10)的平方=0,则(x+y)(x-Y)= x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 .|x-2y-3|+|2x-y+4|=0则x=y= |x减3|+|y减2|=0,则x分之y= ,|x+y|= 已知2x-3y=0则3x-y比x+2y=