已知x²+2xy+y²=5,x²-2xy+y²=1,求x和y
已知x+y=3 xy=-5 求x设abc=1 求x²+3xy+2y²/x²y+2xy
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=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
已知x²+y²-2x+4y+5=0,求X^4-y^4/2x^2+xy-y²·2x-y/xy
已知实数xy满足x²﹢y²-xy+2x-y+1=0求xy
已知实数x,y满足x²+y²-xy+2x-y+1=0 求x y
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
已知:xy=1,x²+y²=2,求:x-y和x+y的值
已知x/y=3,求(x²+2xy-3xy²)/(x²-xy+y²)
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y