问题
解答题
把下列各式因式分解
(1)0.25x2-81y2
(2)x3-2x2y+xy2
(3)a4-18a2+81.
答案
(1)原式=(0.5x+9y)(0.5x-9y);
(2)原式=x(x2-2xy+y2)
=x(x-y)2;
(3)原式=(a2-9)2
=(a+3)2(a-3)2.
把下列各式因式分解
(1)0.25x2-81y2
(2)x3-2x2y+xy2
(3)a4-18a2+81.
(1)原式=(0.5x+9y)(0.5x-9y);
(2)原式=x(x2-2xy+y2)
=x(x-y)2;
(3)原式=(a2-9)2
=(a+3)2(a-3)2.