1.（8+4/11)除以4=2.1.975-1/3除3/8*0=3.12.5*19+11*25/2=4.5/7*2/5除

1.（8+4/11)除以4=33.454545……
2.1.975-1/3除3/8*0=1.975
3.12.5*19+11*25/2=100
4.5/7*2/5除5/7=2.5
二.递等式计算.
5.8*1.7-2.3*0.8
=9.86-1.84
=8.02
6.75*2/5+2/5*6.75
=2.7+2.7
=5.4
(4+7/11)-(1+7/11+7/8)
=4+7/11-1-7/11-7/8
4-1-7/8+(7/11-7/11)
=3-7/8+0
=3-0.875
=2.125
6.75*2/5+2/5*6.75
=2.7+2.7
=5.4

5.4，谢谢采纳！！(*^__^*)...嘻嘻