已知x^2+y^2-4x+y+17/4=0,求y^-x+3xy
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
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=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知2x+3y=0,求代数式1.5x+4y/3x-2y 2.x²+xy-y²/x²-xy+
已知x、y均为实数,且满足xy+x+y=17,x^2y+y^2x=66,求x^4+x^3y+x^2*y^2+y^3x+y
已知x^3+xy^2+x+x^2y+y^3+y=0,求5x-6y/3x+4y的值.
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方