问题
计算题
因式分解:
(1)x2﹣xy﹣12y2;
(2)a2﹣10a+25﹣b2.
答案
解:(1)x2﹣xy﹣12y2
=(x﹣4y)(x+3y);
(2)a2﹣10a+25﹣b2
=(a2﹣10a+25)﹣b2
=(a﹣5)2﹣b2
=(a﹣5+b)(a﹣5﹣b).
因式分解:
(1)x2﹣xy﹣12y2;
(2)a2﹣10a+25﹣b2.
解:(1)x2﹣xy﹣12y2
=(x﹣4y)(x+3y);
(2)a2﹣10a+25﹣b2
=(a2﹣10a+25)﹣b2
=(a﹣5)2﹣b2
=(a﹣5+b)(a﹣5﹣b).