Question

Tính nhanh:

2 x 31 x 12 + 4 x 6 x 42 + 8 x 27 x 3

Answer 1

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 + 24 x 42 + 24 x 27 

= 24( 31+42+27)

=24 x100

=2400

Answer 2

\(2\cdot31\cdot12+4\cdot6\cdot42+8\cdot27\cdot3\)

\(=\left(2\cdot12\right)\cdot31+\left(4\cdot6\right)\cdot42+\left(8\cdot3\right)\cdot27\)

\(=24\cdot31+24\cdot42+24\cdot27\)

\(=24\cdot\left(31+42+27\right)\)

\(=24\cdot100\)

\(=2400\)

dấu . là đấu nhân nha!! 

Answer 3

  2x31x12+4x6x42+8x27x3

=62x12+24x42+216x3

=62x3x4+3x8x42+216x3

=248x3+3x336+216x3

=3x(248+336+216)

=3x800

=2400

Answer 4

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

= 2400

Answer 5

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

=   24 x 31   +   24 x 42   + 24 x 27

=  24  x  ( 31 + 42 + 24 )

=  24  x   100

= 2400

Answer 6

  2 x 31 x12 + 4 x6 x42 +8 x27 x3

= 62 x12+ 24x42 + 216 x3

= 62x3x4+3x8x42+216x3

=248x3+3x336+216x3

=3x(248+336+216)

=3x800

=2400

Answer 7

tốt các em làm rất tốt