Question

tính nhanh

a) 2.31.12+4.6.42+8.27.3

b) 36.28+36.82+64.69+64.41

Answer 1

a)2.31.12+4.6.42+8.27.3

=2.12.31+24.42+8.3.27

=24.31+24.42+24.27

=24.(31+42+27)

=24.100

=2400

b)36.28+36.82+64.69+64.41

=36.(28+82)+64.(69+41)

=36.100+64.110

=3600+7040

=10640

Answer 2

a) 2.31.12 + 4.6.42 + 8.27.3

= 2.12.31 + 4.6.42 + 8.3.27

=24.31 + 24.42 + 24.27

=24.(31+42+27)

=24.100

=2400

b) 36.28 + 36.82 + 64.69 + 64.41

= 36.(28+82) + 64. ( 69 + 41 )

=36.110 + 64. 110

=(36+64).110

=100.110

=11000

Answer 3

a) 2400

b) 36.(28+82)+64.(69+41)

=36.100+64.100

=3600+6400

=10000

Answer 4

a, 2.31.12+4.6.42+8.27.3

= ( 2.12) . 31 + ( 4.6) . 42 + (8.3).27

=24.31 + 24.42 +24.27

=24.( 31 + 42 + 27 )

= 24 . 100

= 2400