(x+y)^2=11,(x-y)^2=7,求xy的值
如果x^2+xy+y-14,y^@+xy+x=28,求x+y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=-1,xy=-2,求代数式-5(x+y)+(x-y)+x(xy+y)的值
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方
已知x-xy=8,xy-y=-9,求x+y-2xy的值
已知x/y=7/2,求2x+3xy+2y/x+2xy+y的值
已知1/x-1/y=5,求分式y+xy-x/2x+7xy-2y的值.
已知1/X-1/y=5,求分式(y+xy-x)/(2x+7xy-2y)的值
x^2+y^2=7,xy=-2,求5x^2-3xy-4y^2-11xy-7x^2+2y^2的值
已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理.
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知x+y=3xy,求2x+2y-xy/x+y+2xy的值、