1、(x^3+x^2-x-1)÷(x-1)
=[x(x²-1)+x²-1]÷(x-1)
=(x+1)²
2、没看懂
3、157
4、(a²+2ab+b²)(a²+2ab-b²)÷(a+b)²
=a²+2ab-b²
5、x(x²-y²)/-(x+y)=-x(x-y)
1、(x^3+x^2-x-1)÷(x-1)
=[x(x²-1)+x²-1]÷(x-1)
=(x+1)²
2、没看懂
3、157
4、(a²+2ab+b²)(a²+2ab-b²)÷(a+b)²
=a²+2ab-b²
5、x(x²-y²)/-(x+y)=-x(x-y)