4/9除7/45除0.625=?4.15-3.75乘10/1-8/5=?

4/9除7/45除0.625=?4.15-3.75乘10/1-8/5=?
4/9除7/45除0.625=?4.15-3.75乘10/1-8/5=?

4/9除7/45除0.625=?4.15-3.75乘10/1-8/5=?
4/9÷7/45÷0.625
=4/9*45/7÷5/8
=20/7*8/5
=32/7
(4.15-3.75)*10/1-8/5
=(4.15-3.75)*10-1.6
=0.4*10-1.6
=2.4