x+y=1,xy=-2求(x²+y²+xy)/(x²+y²-xy)

已知x:y=3:2,求(x²+3xy)/(xy+2xy) 已知实数xy满足x²﹢y²-xy+2x-y+1=0求xy 若x=1/2,y=1 求x(x²+xy+y²)-y(x²+xy+y²)+3xy( X²+2xy+y²/xy乘x²-2xy+y²/xy+y²= 计算：(xy-x²)×x-y/xy 已知X²+Y²+X²Y²-4XY+1=0 求:（X-Y)^2008-(XY)^2 已知x+y=2,xy=1/2,求x³y+2x²y²+xy³ 已知x/y=3,求(x²+2xy-3xy²)/(x²-xy+y²) 1/x+1/y=5,求2x-3xy+2y/x²+xy+y的值 已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值 已知x+y=3 xy=-5 求x设abc=1 求x²+3xy+2y²/x²y+2xy
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y