问题 解答题

计算:

(1)分解因式:6xy2-9x2y-y3

(2)(a2b-2ab2-b3)÷b-(a+b)(a-b)

答案

(1)6xy2-9x2y-y3

=-y(9x2-6xy+y2),

=-y(3x-y)2

(2)(a2b-2ab2-b3)÷b-(a+b)(a-b),

=a2-2ab-b2-a2+b2

=-2ab.

单项选择题
填空题