①a²-b²-2b-1 ②a四次方-9-6b-b² ③ x三次方+2x

①a²-b²-2b-1 ②a四次方-9-6b-b² ③ x三次方+2x

①a²-b²-2b-1=a²-(b+1)²=(a+b+1)(a-b-1)②a四次方-9-6b-b² =a^4-(3+b)²=(a²-3-b)(a²+3+b)③ x三次方+2xy-x-xy²=x(x²-y²-1+2y)=x[x²-(y-1)²]=x(x-y+1)(x+y-1)======以下答案可供参考======供参考答案1:①a²-b²-2b-1=a²-(b+1)²=(a+b+1)(a-b-1)②a四次方-9-6b-b² =a^4-(3+b)²=(a²-3-b)(a²+3+b)③ x三次方+2xy-x-xy²=x(x²-y²-1+2y)=x[x²-(y-1)²]=x(x-y+1)(x+y-1) 我同样上七年级，同胞啊·······希望能帮到你，求采纳，O(∩_∩)O谢谢供参考答案2:①a²-b²-2b-1=a²-（b²+2b+1）=a²-(b+1)²=(a+b+1)(a-b-1)②a四次方-9-6b-b²=a四次方-(9+6b+b²)=a四次方-(b+3)²=(a²+b+3)(a²-b-3)③ x三次方+2xy-x-xy²=x(x²+2y-1-y²)=x[x²-(y²-2y+1)]=x[x²-(y-1)²]=x(x+y-1)(x-y+1)供参考答案3:a²-b²-2b-1=a²-（b²+2b+1)=(a-b-1)(a+b+1）a^4-9-6b-b^2=a^4-(b+3)^2=(a^2-b-3)(a^2+b+3)x^3+2xy-x-xy^2=x(x^2+2y-1-y^2)=x(x-y+1)(x+y-1)

这个答案应该是对的