⑴2/3＋（4/7＋1/2）×7/25

=2/3＋4/7×7/25＋1/2×7/25

=2/3＋(4/25＋7/50)

=2/3＋3/10

=29/30

⑵16.6×0.54＋1.66×3.6＋1.66

=1.66×5.4＋1.66×3.6＋1.66×1

=1.66×(5.4＋3.6＋1)

=1.66×10

=16.6

⑶1/3÷5/4＋2/3×4/5

=1/3×4/5＋2/3×4/5

=(1/3＋2/3)×4/5

=1×4/5

=4/5

⑷7又2分之1÷[3又4分之3×（35分之4－2又3分之2）]

=15/2÷[15/4×（4/35－8/3）]

=15/2÷(15/4×4/35－15/4×8/3）

=15/2÷(3/7－10）

=15/2÷(-67/7)

=-105/134【此原题可能有误】

愿对你有所帮助！