题目因式分解:(1)2ax2−18a3(1)2ax^{2}-18a^{3}(1)2ax2−18a3；(2)6x2−7x−5(2)6x^{2}-7x-5(2)6x2−7x−5；(3)x3−xyz+x2y−x2z(3)x^{3}-xyz+x^{2}y-x^{2}z(3)x3−xyz+x2y−x2z；(4)(x2−3x+1)2−6x2+18x−1(4)(x^{2}-3x+1)^{2}-6x^{2}+18x-1(4)(x2−3x+1)2−6x2+18x−1.知识点：单项式乘多项式章节：未标注
