已知x+3y=-2,则1/2*x²+3xy+9/2*y²=
已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y
已知X/Y=2,则X²+2XY-3Y²/X²-XY+Y²=?
已知xy/x+y=1/2,则代数式3x-5xy+3y/-x+3xy-y=
已知x²-3xy+4x=3,y²+xy-4y+7=0,则xy-1/2(x²+y²
已知:X+Y=-3,XY=2,X²Y+XY²
已知x+y=3 xy=-5 求x设abc=1 求x²+3xy+2y²/x²y+2xy
已知x-y=4xy,则2x+3xy-2yx-2xy-y
已知x/y=3,求(x²+2xy-3xy²)/(x²-xy+y²)
已知x/y=3,求x²+2xy-3y²/x²-xy+y²
已知y分之x=3,求x²-xy+y²分之x²+2xy-3y²
已知x/y=3,求x²+2xy-3y²/x²-xy+y²的值
已知y/X=3,求x²-xy+y²/x²+2xy-3y²的值