x²-2xy-8y²-x-14y-6=x²-(2xy+x)-(8y²+14y+6).分组=x²-(2y+1)x-(8y²+14y+6).提取公因式=x²-(2y+1)x-(4y+3)(2y+2).十字相乘=[x-(4y+3)][x+(2y+2)].十字相乘=(x-4y-3)(x+2y+2)...