解
a,b互为倒数,则
ab=1
(b/9)÷(2/3)×(a/4)——这个吗
=(b/9)×(3/2)×(a/4)
=(ab)/(24)
=1/24
(5/a÷b/6-15)÷3/5
=(5/a×6/b-15)×5/3
=(30/ab-15)×5/3
=(30-15)×5/3
=15×(5/3)
=25