1.02/(5+0.4*0.25)【6.85-(0.65+0.7)】/2.5
=1.02/(5+0.1)(6.85-1.35)/2.5
=1.02/5.1*5.5/2.5
=0.2*5.5/2.5
=1.1/2.5
=0.44