1)93.52-38.43+93.38-43.52=93.52-43.52+93.38-38.43=
=52.(93-43)+38.(93-43)=52.50+38.50=50.(52+38)=50.90=4500
2)12,7.3,4+8,2.1,4-1,4.12,7-3,4.8,2=12,7.3,4-1,4.12,7+8,2.1,4-3,4.8,2=
=12,7.(3,4-1,4)+8,2.(1,4-3,4)=12,7.2+8,2.(-2)=12,7.2-8,2.2=
=2.(12,7-8,2)=2.4,5=9
3)78,5²+21,5.93,4-21,5.14,9=78,5.78,5+21,5.(93,4-14,9)=
=78,5.78,5+21,5.78,5=78,5.(78,5+21,5)=78,5.100=7850