题目内容
A.7ab(-2a+3b) B.-7ab(2a-3b+1)
C.-7ab(-2a+3b-1) D.-7ab(2a-3b)
对下列多项式进行因式分解
(1)-9x2y+3xyz
(2)x(y-z)-y(z-y)
(3)81x2-y4
(4)+a2+a4
(5)(x+y)2-4(x+y-1)
(6)x4-16
(7)14a2b-49a3b-ab