1.a)A=37.173+62.173+173
=(37+62+173).173=272.173=47056
b)B=72.99+28.99-900
=99.(72+28)-900=99.100-900
=990-900=90
c)C=2mũ 3 .3-(1mũ 10 + 15):4 mũ 2
=8.3-(1+15):16=8.3-16:16=16-1=15
d)D=6 mũ 2 :4.3 +2.5 mũ 2 -201mũ 0
=36 :4.3 +6,25-0=8.37+6,25=14,62
2.a)121020
x=1 ;y=0
b)413325
x=3;y=5