若2x²+xy+3y²=-5,求（9x²+2xy+6）-（xy+7x²-3y&#

已知x:y=3:2,求(x²+3xy)/(xy+2xy) 已知x/2=y/3（xy≠0）,求x²-2xy-3y²/x²-6xy-7y²的值 已知xy²=-6,求xy(x^3y^7-3x^2y^5-11.5y)的值 已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值 若x²＋y²=7,xy=-2,求5x²-3xy-4y²-11xy-7x² 已知x/y=3,求(x²+2xy-3xy²)/(x²-xy+y²) 若x=1/2,y=1 求x(x²+xy+y²)-y(x²+xy+y²)+3xy( 求3x²y-2xy²+2（xy-二分之三x²y）-xy+3xy²的值,其中x=3 已知x/y=2,求x²-xy+3y²/x²+xy+6y²的值 已知x+y=3 xy=-5 求x设abc=1 求x²+3xy+2y²/x²y+2xy
1/x+1/y=5,求2x-3xy+2y/x²+xy+y的值 已知2X-3√xy-2y=0(x>0)求2x²+xy-9y²分之x²+4xy-16y