13.6x42.3x3.75—12.5x0.423x28

13.6x42.3x3.75—12.5x0.423x28
=42.5*(13.6*15/4-4.5)
=42.5*(3.4*15-4.5)
=42.5*46.5
=44.5^2-4
=1976.25
16x14.97÷1996
=4*14.96/499
=5984/49900
75x4.67+17.9x2.5
=25*(14.01+1.79)
=25*15.8
=1580/4
=395
19.98x37+199.8x2.3+9.99x80
=19.98*(37+23)+800-0.8
=19.98*60+800-0.8
=1198.8-0.8+800
=1998