4.(1)解:原式=-(91÷13)
=-7
(2)解:原式=56÷14
=4
(3)解:原式=-(16÷3)
=-16/3
(4)解:原式=48÷16
=3
(5)解:原式=-(4/5÷1)
=-4/5
(6)解:原式=-(0.25÷3/8)
=-(1/4÷3/8)
=-2/3
6.(1)解:原式=-3(2)解:原式=-1/12(3)解:原式=27/4(4)解:原式=20
没有