已知|x+y+2|+(2x-3y-1)2=0,则4x2-5xy+y3=______.
已知x+y=4,xy=2,则x2+y2+3xy=______.
已知x+y=1,则代数式x3+3xy+y3的值是______.
已知x+y+z=1,x2+y2+z2=2,x3+y3+z3=3,求xy(x+y)+yz(y+z)+zx(z+x)的值
已知xy=3,x2+xy-2y2=2(x+2y),且x≠-2y,则x+y=______.
实数x,y满足x≥y≥1和2x2-xy-5x+y+4=0,则x+y=______.
若2x+y=0,则代数式4x3+2xy(x+y)+y3的值为______.
已知:x+y=1,xy=-3,求下列各式的值:(1)x2+y2; (2)x3+y3; (3)x5y+xy5.
已知实数x、y满足x2+4xy+4y2+x+2y-6=0,则x+2y的值为______.
若有理数x,y满足方程(x+y-2)2+|x+2y|=0,则x2+y3=______
已知A(X1,Y2)B(X2,Y2)C(X3,Y3)在y=2^x 上 X1+2X2+3X3=1 则Y1+Y2^2+Y3^
已知x2+y2-2x-4y+5=0,则1xy+1(x+1)(y+1)+1(x+2)(y+2)+…+1(x+2010)(y
已知x2+y2-2x+4y+5=0,求(x^4-y^4)/(2x^2+xy-y^2)·[(2x-y)/(xy-y^2)]