因式分解(三)1.多项式-6ab2+18a2b2-12a3b2c的公因式是( ) A.-6ab2c B.-ab2 C.-6ab2 D.-6a3b2c2.下列用提公因式法因式分解正确的是( )A.12abc-9a2b2=3abc(4-3ab) B.3x2y-3xy+6y=3y(x2-x+2y)C.-a2+ab-ac=-a(a-b+c) D.x2y+5xy-y=y(x2+5x)3.下列多项式应提取公因式5a2b的是( )A.15a2b-20a2b2 B.30a2b3-15ab4-10a3b2C.10a2b-20a2b3+50a4b D.5a2b4-10a3b3+15a4b24.下列因式分解不正确的是( &nb..