1.65*56+4.4*18+0.56*15
=1.65*3*18+4.4*18+3*18*0.15
=18*（1.56*3+4.4+0.15）
=18*9.23
=166.1451.2*23*4+35.9*48.851.2*23*4+35.9*48.8=50×23.4+1.2×23.4+50×35.9-1.2×35.9=1170+1795-1.2×12.5=2965-15=2950