x²-3xy-18y²-3x-9y分解因式

若x²+xy-2y²=0,则x²+3xy+y²/x²+y² x²+xy-2y²=0则x²+3xy+y²/x²+y² 计算：4xy²-3x²y-{3x²y-[2xy²-4x²y+2(x²y-2xy²)]急 3x²-y²=8x²＋xy＋y²=4 6x²-xy-15y²=0 求x²-2xy+4y²/2x²-3xy-3y²告诉下 6x²-xy-15y²=0 求2x²-3xy-3y²分之x²-2xy+4y² 已知：x²+xy=3,xy+y²=-2 求：2x²-xy-3y² 6x²y-9xy-xy²+3x²y 3x³ - 6x²y+ 3xy² 因式分解X²-3Xy+2y²+X-2 因式分解 x²-3xy+2y²+x-2 已知x² -XY = 2,Y² -XY= 5,求x² - 4x Y+ Y² = 2x² + xY -3Y² = x² 已知x² -XY = 2,Y² -XY= 5,求x² - 4x Y+ Y² = 2x² + xY -3Y² = x² + xY- 2Y² =求x² - 4x Y+ Y² = x/y=2,求x²-3xy+y²/2x²-3xy+5y² 已知x/y=3,求x²+2xy-3y²/x²-xy+y²的值 已知x/y=3,求x²+2xy-3y²/x²-2xy+y² x/y=2,求分式x²-xy+3y²/x²+xy+6y² 1.y²-5xy-6x² 2.m²-3mn+2n² 计算 ①[x(x²y²-xy)-y(x²-x³y)]÷3x²y