问题 解答题

把下列各式分解因式.

(1)x3-9x

(2)xy-5x-y+5.

答案

(1)x3-9x

=x(x2-9)

=x(x+3)(x-3);

(2)xy-5x-y+5

=(xy-5x)+(-y+5)

=x(y-5)-(y-5)

=(y-5)(x-1).

单项选择题
单项选择题