4x²y³﹙2x²-3xy+5y²﹚÷﹙﹣4x²y²﹚
(3x+2y)(9x²-6xy+4y²﹚
[xy(x²-3y)+3xy²]﹙﹣2xy﹚+x³y²﹙2x-y﹚ 其中x=﹣1
已知:x²+y²-2x+4y+5=0,求﹙y/x²-xy﹚-﹙x/xy-x²﹚的
f(x+y,xy)=x²+y²,则f﹙x,y﹚=?函数z=2xy-3x²-3y²
已知x/y=2,求2x(x+y)-y(x+y)/4x²-4xy+y²
急![(3x+y)²-3(3x-y)(x+y)-(x-3y)(x+3y)]÷(2xy)
先化简再求值xy﹙x²+y﹚-y²﹙xy+2x﹚-3xy²,其中x=5,y=﹣1
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
(2x²y-3xy²)-3(x²y-2xy²)+2(x²y-4xy
(-x-2y)(x²-2xy+4y²)
多项式因式分解 1,(x-y)³-(x-y)²(x+y) 2,x(x²-xy)-(4x
2x+y=0,求4x²+2xy(x+y)+y³