Question

tính nhanh:2*31*12+4*6*42+8*27*3

Answer 1

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

Answer 2

2*31*12+4*6*42+8*27*3

=24*31+24*42+24*27

=24*[31+42+27]

=24*100

=2400

Answer 3

2 x 31 x 12 + 4 x 6 x 42 + 8 x 3 x 27

= 24 x 31 + 24 x 42 + 24 x 27

= 24 x ( 31 + 42 + 27 ) 

= 24 x 100

= 2400 

Answer 4

2 x 31 x 12 + 4 x 6 x 42 + 8 x 27 x 3

= { 2 x 12 } x 31 + { 4 x 6 } x 42 + { 8 x 3 } x 27

= 24 x { 31 + 42 + 27 }

= 24 x 100

= 2400

Answer 5

2x31x12+4x6x42+8x27x3

=(2x12)x31+(4x6)x42+(8x3)x27

=24x(31+42+27)

=24x100

=2400

Answer 6

2x31x12+4x6x42+8x27x3

=(2x12)x31+(4x6)x42+(8x3)x27

=24x(31+42+27)

=24x100

=2400

Answer 7

2x31x12+4x6x42+8x27x3

=(2x12)x31+(4x6)x42+(8x3)x27

=24x(31+42+27)

=24x100

=2400

Answer 8

2x31x12+4x6x42+8x27x3

=(2x12)x31+(4x6)x42+(8x3)x27

=24x(31+42+27)

=24x100

=2400

Answer 9

2x31x12+4x6x42+8x27x3

=(2x12)x31+(4x6)x42+(8x3)x27

=24x(31+42+27)

=24x100

=2400