Question

1、化简x^2(x+1)-x(x^2-1)-x-7

Answer 1

1、化简x^2(x+1)-x(x^2-1)-x-7

=x^3+x^2-x^3+x-x-7

=x^2-7

2、化简(a^2b-2ab^2-b^3b-(a+b)(a-b)

=b(a^2-2ab-b^2)b-(a^2-b^2)

=a^2-2ab-b^2-a^2+b^2

=2b^2-2ab

3、化简x(x+2)-(x+1)(x-1)

=x^2+2x-x^2+1

=2x+1

4、化简（a+b)(a-b)+b(b-2)

=a^2-b^2+b^2-2b

=a^2-2