(1) a3-2a2+a (2)ax2-8ax+16a (3)a3b-2a2b2+ab3 提取公因式,

(1) a3-2a2+a=a（a2-2a+1）=a（a2-2a+1)=a(a-1)(a-1)
(2)ax2-8ax+16a =a(x2-8x=16)=a(x-4)(x-4)
(3)a3b-2a2b2+ab3 =ab(a2-2ab=b2)=ab（a-b）（a-b）

(1)=a(a-1)^2
(2)=a(x-4)^2
(3)=ab(a^2-2ab+b^2)=ab(a-b)^2