若x+y=-1,求x⁴+5x³y+x²y+8x²y²+xy²
已知x+y=1,xy=-二分之一,求x(x+y)(x-y)-x(x+y)²
已知x²+y²-8x+6y+25=0,求(x-y+4xy/x-y)(x+y-4xy/x+y)
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
x²/xy-x/y
2x+y=0,求4x²+2xy(x+y)+y³
若正数x,y满足x²-y²=2xy,求(x-y)/(x+y)的值
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
若x-y=6,xy=-8,求代数式(x+y+z)²+(x-y-z)(x-y+z)-2·z(x+y)的值
已知x+y=2,xy=1/2,求x³y+2x²y²+xy³
若x²+xy+5y=3,y²+xy+5x=-3,求x+y的值.
若x²+xy+5y=3,y²+xy+5x=-3,求x+y的值
若x²+xy+5y=3,y²+xy+5x=-3,求x+y旳值