-71(3/4)-[-3(1/2)]+4/3-8.5
=-71(3/4)+3(1/2)+4/3-4(1/2)
=-71(3/4)-1+4/3
=-72(3/4)+4/3
=-72(9/12)+16/12
=-71(21/12)+16/12
=-71(5/12)
负71又12分之5
-71(3/4)-[-3(1/2)]+4/3-8.5
=-71(3/4)+3(1/2)+4/3-4(1/2)
=-71(3/4)-1+4/3
=-72(3/4)+4/3
=-72(9/12)+16/12
=-71(21/12)+16/12
=-71(5/12)
负71又12分之5