(1)-8ab-3ab-9ba (2)1/3xy-1/2xy+7/6xy

问题描述:

(1)-8ab-3ab-9ba (2)1/3xy-1/2xy+7/6xy
列式

(1)-8ab-3ab-9ba
=(-8-3-9)ab
=-20ab
(2)1/3xy-1/2xy+7/6xy
=(1/3-1/2+7/6)xy
=xy