合并同类项ab-c-[2(ab-c)+(-3ab+c+2ab)+c-ab

更新时间2022-08-19 15:35:15

ab-c-[2(ab-c)+(-3ab+c+2ab)+c-ab]

=ab-c-[2(ab-c)-(ab-c)-(ab-c)]

=ab-c-0

=ab-c