用递等式计算下面各题能简算的要简算1又九分之七减九分之七÷八分之七 18又九分之七÷五分之11加3又

楼上第一题错了.先算除.
1又7/9-7/9÷7/8
=16/9-7/9×8/7
=16/9-8/9
=8/9分号右边是分母
18又7/9÷11/5+3又2/9×5/11
=169/9×5/11+29/9×5/11
=(169/9+29/9)×5/11
=199/9×5/11
=995/99
28×(14/7+33/4)
=28×14/7+28×33/4
=56+231
=287
12÷(2/3-1/4)
=12×3/2+12×4
=18+48
=76
3/4×8/13÷(2/3×8/13)
=3/4×8/13÷2/3÷8/13
=6/13×13/8×3/2
=8×3/2
=12
5/14÷[6/7×(2/3+1/6)
=5/14÷[6/7×5/6]
=5/14÷5/7
=5/14×7/5
=1/2
纯手打,
=

1又九分之七减九分之七÷八分之七
=1÷八分之七
=8/7
18又九分之七÷五分之11加3又？
=