①y²-16；②x³y-xy³；③x²+14x+49；④18a^4x²+24a²x²y+8x²y²

①y²-16；②x³y-xy³；③x²+14x+49；④18a^4x²+24a²x²y+8x²y² 约分,急① X³-2X²Y/X²-2XY²②a²-（b-c）²/(a+b)²-c² x³y³-x²y²-xy+1 x³-x²y-xy²+y³(因式分解) (x+y)²-（x³+y³)÷（x+y) 计算 ①[x(x²y²-xy)-y(x²-x³y)]÷3x²y 16x²-64 y³4xy²+4x²y 指出下列多项式的次数和项数.①3x²-2x²y+4x²y²②-2+4x²y-1/2xy²-3y³+5y^4 用平方差公式进行因式分解 计算①4（x+y）²-9（x-y）²②9m²（a-b）³-49（b-a）³③（x+y-z）²-（x-y+z）²④x-x²-y+y²⑤（3x-y）²-4x²⑥（x+y）²-x²y²★⑦ ①.X²-2X+1/X²-1 ÷ X²-X/X+1②.a-1/a²-4a+4 ÷ a²-1/a²-4③.x³-x²/x²-x ÷ x²-2x/x-1④.(x-y)²/x+y ÷ 1/y+x X 1/x-y帮下忙嘛 咯 用韦达定理解题x/（2¹º+5³）+y/（2¹º+6³）=1①｛x/（3¹º+5³）+y/（3¹º+6³）=1求x+y=?②x²y+xy²=880求x²+y²=?x+y+z=a③｛x²+y²+z²=（1/2）a&s 数学分式约分约分这个分式：x³y-xy³/x³-2x²y+y²x（有步骤）还有一个：x³-16x/x²-8x+16（有步骤） 16x³-24x²y²+12xy^4-2y^6 ①4(a+b)²-9a+9b②x²/25-y²/16③-3x+6x²-3X的³④0.1a的四次方+0.8a²+1.6⑤[（3x-7)²-(x+5)²]÷（4x-24)第一题错掉了、是①4(a-b)²-9a+9b ①先简化,再求值.3a²+b-[2a²b-(2abc-a²b)-4a²c]-abc,其中a=-2,b=-3,c=1②(0.3x²-x²y+xy²-y³)-(-0.5x³-x²y+0.3xy²)写出过程的都+分 化简4x³(-y³)²-3x·(-x)²(-y²)³化简4x³(-y³)²-3x·(-x)²(-y²)³ 化简再求值 4x³（-y³）²-3x×（-x）²（-y²）³滚 因式分解 4xy²-4x²y-y³