1、x ³ + 9 + 3x ² +3x =x ³+ 3x ² +3x+9 =x ²（x+3）+3(x+3)=(x²+3)(x+3)2、 题目有错吧3、a³+1 =(a+1)(a²-a+1)4、4xˆ4-13x²+9 =(x²-1)(4x²-9) =(x+1)(x-1)(2x+3)(2x-3)
