化简在求值-5y²+{2xy-[y²+x²-(1-y²)+2xy]+3x
化简在求值-5y²+{2xy-[y²+x²-(1-y²)+2xy]+3x
化简求值3x²y-[2xy-2(xy-3/2x²y)+xy]+3xy²其中x=3、y=-1
化简求值:x-y/x²-2xy+y²-xy+y²/x²-y²,其中(x
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,
化简求值:(-1/3XY)²[xy(2x-y)-2x(xy-y²)],其中X=-3/2,Y=-2
化简求值[1-(2x/x+y)]÷ (x²-2xy+y²/3x+3y)+(x²+xy/x&
先化简,再求值:{xy(x²-3y)+3xy²}(-2xy)+x³y²(2x-y
先化简在求值:(-1/3XY)²×[xy(2x-y)-2x(xy-y)²],其中X=-3/2,Y=2
先化简在求值:(-1/3XY)²×[xy(2x-y)-2x(xy-y)²],其中X=-3/2,Y=-
数学:先化简再求值(x²+xy-2y²/x²-2xy+y²)-(1-xy
化简求值3x²y-[2xy²-2(xy-3/2x²y)+xy]+3xy² ,当x
先化简在求值(x+y)²-(x-y)(x+y)-(xy)²÷(xy),其中x,y是方程组『3x+2y