6.72*3.6+37.8*0.36
=6.72*3.6+3.78+3.6
=(6.72+3.78)*3.6
=10.5*3.6
=37.8
369*0.99+3.69
=3.69*99+3.69
=3.69*(99+1)
=369
(0.64+0.32)/0.64
= 0.64/0.64+0.32/0.64
=1+0.5
=1.5
13.5*2.5-0.35*25
=13.5*2.5-3.5*2.5
=(13.5-3.5)*2.5
=10*2.5
=25