若（x+1)^2+|y-2|=0,求3x^2-[5xy-(x^2y-3xy)+4x^2y-8xy]的值

若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 若(2x-y-1)2+|x-2y-3|=0,求代数式(2x+y)(2x-y)-(x+2y)(x-2y-1)的值若(2x-y-1)²+|x-2y-3|=0,求代数式(2x+y)(2x-y)-(x+2y)(x-2y-1)的值 若(x+y)(x+y-1)-2=0,求x+y的值求 若x^5+x^4y+x^4+x+y+1=0,且3x+2y=1,求x,y的值 求导数y=3x-x^2 求y',y'/ x=1 y'/x=0 若|x-1|+|2x+4y|=0,求3x-2y 若|x+y-1|+（x-y-2)²=0,求代数式（x+2y)(x-2y）-（2x-y)(-y-2x)的值. 若x*x+y*y=x+y-1/2,求x,y的值如题 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 若x+y+3=0,求2/3-2x-2y+(-x-y)^2 x²-4x-1=0,求(2x-3)²-(x+y)(x-y)-y² 若2x-3y=0,求5x+4y/3x-2y 若根号x+y-3+绝对值xy+x+y-2=0,求x/y+y/x根号x+y-3+绝对值xy+x+y-2=0,求x/y+y/x 若x-y=3,x^2-y^2=1,求x+y的值 3x+4y-5=0 x^2+y^2=1求x.y 若／X+Y-9／+（2X-Y+3)=0求X与Y的值 已知|2x-3y|+|3x-y-1|=0,求x,y的值. 1、若x>-1,求y=x+1/x+1的最小值,并求对应的x的值 2、y=x²+4/x(x>0),求y的最小值3、若x>=0,求y=x²+x+2/x+1的最小值4、求y=x(9-3x)的最大值(0