-1/3x²y²+xy=( )(xy-3)
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
化简求值3x²y-[2xy-2(xy-3/2x²y)+xy]+3xy²其中x=3、y=-1
已知x:y=3:2,求(x²+3xy)/(xy+2xy)
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,
若x=1/2,y=1 求x(x²+xy+y²)-y(x²+xy+y²)+3xy(
3xy²-[xy-2(xy-3/2x²y)+3xy²]+3xy²,其中x=3,y
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
已知x/y=3,求(x²+2xy-3xy²)/(x²-xy+y²)
下列多项式:(1)x²+xy-y²;(2)-x²+2xy-y²;(3)xy+x&
1/x+1/y=5,求2x-3xy+2y/x²+xy+y的值
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1