已知x+y=6,xy=4,则x2+y2=______;(x-y)2=______.
已知x+y=4,xy=2,则x2+y2+3xy=______.
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x2+4x+y2-2y+5=0,则x2+y2=______.
已知xy=3,x2+xy-2y2=2(x+2y),且x≠-2y,则x+y=______.
已知x+y=5,xy=3 则x2+y2=______.
已知x+y=17,xy=60,则x2+y2=______.
已知xy=-3,x+y=-4,则x2+3xy+y2值为______.
已知x2-4y2=20,x+2y=5,则x=______,y=______.
已知x-y=2,则x2-y2-4y=______.
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______.
若x+y=5,xy=6,则x2+y2=______.