a) 571+216+129+124 b) 27.74+26.27-355 c) 100:{250:[450-(4.5^3-2^2.25)]}

=(571+129)+(216+124) =27.(74+26)-355 =100:{250:[450-(4.125-4.25)]}

=700+340 =27.100-355 =100:{250:[450-(500-100)]}

1040 =2700-355 =100:{250:[450-400]}
=2345 = 100:{250:50}

=100:5

=20

a) số chia hết cho 2 : 320;4914;90.

b) số chia hết cho 5: 320;2315;90.

c) số chia hết cho 3: 2315;90;543;4914.

d) số chia hết cho 2;3;5;9: 4914;90.