已知x2-y2=12,x+y=6,则x-y=______,x=______,y=______.
已知x2-y2=12,x+y=6,则x-y=______,x=______,y=______.
已知x2+4x+y2-2y+5=0,则x2+y2=______.
已知x2-4y2=20,x+2y=5,则x=______,y=______.
已知x-y=2,则x2-y2-4y=______.
若x2-4x+y2+6y+13=0,则x=______,y=______.
已知x+y=-5,xy=6,则x2+y2=______.
已知x2+y2+z2-2x+4y-6z+14=0,则x+y+z=______.
x2-y2=55,x-y=5,则x+y=______.
已知x2+y2-6x+4y+20,它的最小值是______,此时x=______,y=______.
已知x+y=5,xy=3 则x2+y2=______.
已知x+y=17,xy=60,则x2+y2=______.
已知x+y=4,xy=2,则x2+y2+3xy=______.