问题
解答题
因式分
(1)a2(x-y)-4b2(x-y)
(2)a3+6a2+9a
(3)m2+2n-mn-2m
(4)x2-7x+10.
答案
(1)原式=(x-y)(a2-4b2)=(x-y)(a-2b)(a+2b);
(2)原式=a(a2+6a+9)=a(a+3)2;
(3)原式=(m2-mn)+(2n-2m)=m(m-n)-2(m-n)=(m-n)(m-2);
(4)原式=(x-2)(x-5).