x^2-2xy+2y^2+4y+4=0,求x^y,3Q
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知x,y>0 2x+y+3=xy 求5x+4y最小值
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*
已知(x+2)^2+|x+y+5|=0,求3x^2y-[2x^2y-(2xy-x^2y)-4x^2]-xy
已知(x+2)^2+|x+y+5|=0,求3x^2y+{-2X^2y-[-2xy+(x^2y-4x^2)]-xy}
已知x^2+3xy-4y^2=0(y≠0),求x-y/x+y的值.
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值!
xy=-2,x+y=3,求代数式(4xy+12y)+[7x-(3xy+4y-x)]
2x+y=0,求4x²+2xy(x+y)+y³
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
若x-y=4,xy=1,求(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值