已知x2+4x+y2+2y+5=0,则xy=______.
已知x+y=4,xy=2,则x2+y2+3xy=______.
已知x2+4x+y2-2y+5=0,则x2+y2=______.
已知x、y是实数且满足x2+xy+y2-2=0,设M=x2-xy+y2,则M的取值范围是______.
已知x+y=5,xy=3 则x2+y2=______.
已知x+y=-5,xy=6,则x2+y2=______.
已知实数x、y满足x2+4xy+4y2+x+2y-6=0,则x+2y的值为______.
已知xy=-3,x+y=-4,则x2+3xy+y2值为______.
已知x2+4y2+x2y2-6xy+1=0,求 x4-y4/2x-y 乘 2xy-y2/xy-y2 除以(x2+y2/x
已知x+y=17,xy=60,则x2+y2=______.
已知x2+xy=5,xy+y2=-1,则x2-y2=______.
已知2x-3*根号(xy)-2y=0(x>0),则x2+4xy-16y2除以2x2+xy-9y2的值是多少?
已知xy=3,x2+xy-2y2=2(x+2y),且x≠-2y,则x+y=______.