已知x^2+xy=12,且xy+y^2=13,求x^2+y^2,x^4+y^4
已知x-y=4xy且xy≠0,求代数式-x-2xy+y分之2x+3xy-2y的值
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=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知X+Y=2XY,求4X-5XY+4Y 除以X+XY+Y 的值
已知:x-y=1,xy=-2.求:(-2xy+2x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
.已知:x-y=1,xy=-2.求:(-2xy+2 x+3y)-(3xy+2y-2x)-(x+4y+xy)的值
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
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^2+xy=12,且xy+y^2=13,求x^2+y^2
xy=-2,x+y=3,求代数式(4xy+12y)+[7x-(3xy+4y-x)]
已知x-2y=2且xy=3求x²+3xy+4y²的值
已知x-y=3,xy=1,求(-2x+2x+3y)-(3xy+2y-2x)-(x+4y+xy)