计算:-2y³+(3xy²-x²y)-2(xy²-y³)
有这样一道计算题:“计算(2x³-3x²y-2xy²)-(x³-2xy²
先化简,再求值:3xy²(-x²y+2x³y²)-4xy(-xy²)·
x³y³-x²y²-xy+1
已知x/y=3,求x²+2xy-3y²/x²-xy+y³的值
1.已知2x-y=1/3,xy=3,求4x³y-4x²y²+xy³的值(要有计算
已知xy²=-2,求-xy(x³y七次方-3x²y五次方-y)
因式分解:m³-2m²-4m+8;x²-2xy+y²-9
函数极限例题(急)急求Y=X³-4X²+2XY-Y²的极限
7-2xy-3x²y³+5x³y²z-9x⁴y³z&sup
计算:(1).(-2xy²)*(3x²y)²
16x³-24x²y²+12xy^4-2y^6
1已知X-Y=XY=3求(X+Y)²及X³-Y³的值