已知x+2y=5,xy=1.则2x2y+4xy2=______.
已知x+2y=5,xy=1.则2x2y+4xy2=______.
已知x+y=6,xy=4,则x2y+xy2的值为______.
若x-y=3,xy=-2,则xy2-x2y的值是______.
若x+y=5,xy=6,则x2y+xy2的值为______.
如果2x+y=4,xy=3,那么2x2y+xy2的值为______.
已知x+y=-5,xy=7,求x2y+xy2-x-y的值.
若实数x,y满足xy+x+y+7=0,3x+3y=9+2xy,则x2y+xy2=______.
已知(x-2)2+|y+1|=0,求5xy2-[2x2y-(3xy2-2x2y)]的值.
先化简,再求值(3x2y-2xy2)-(xy2-2x2y),其中x=-1,y=2.
若x+y=2,xy=-4,求x2y+xy2+1的值
已知x、y是正整数,并且xy+x+y=23,x2y+xy2=120,则x2+y2=______.
已知A=8x2y-6xy2-3xy,B=7xy2-2xy+5x2y,若A+B-3C=0,求C-A.