a,2*125*2002*8,5
bằng 300*17017
bằng 5105100

a) 2.125.2002.8.5
=(2.5).(125.8).2002
=10.1000.2002
=20020000

b) 36.42+2.17.18+9.41.6

=36.42+17.36+41.36

=36.(42+17+41)

=36.100

=3600

c)28 x 47 + 28 x 43 + 72 x 29 + 72 x 61
= 28 x ( 47 + 43 ) + 72 x ( 29 + 61 )
= 28 x 90 + 72 x 90
= 90 x ( 28 + 72 )
= 90 x 100
= 9000
d)26.54+52.73
=13.2.54+13.4.73
=13.108+13.292
=13.(108+292)
=13.400
=5200