\(a,2\times134\times50\)

\(=\left(2\times50\right)\times134\)

\(=100\times134\)

\(=13400\)

\(b,397\times20+397\times82-397\times2\)

\(=397\times\left(20+82-2\right)\)

\(=397\times100\)

\(=39700\)

=397x100=39700

= 397 x (20 + 82 - 2)

= 397 x (102 - 2)

= 397 x 100

= 39700

\(397\times20+397\times82-397\times2\\ =397\times\left(20+82-2\right)\\ =397\times100=39700\)

    1210 + 397 + 2790 + 503

= (1210 + 2790) + (397 + 503)

= 4000 + 900

= 4900 

=(1210+2790)+(397+503)

=      4000      +    900

=     4900

1210 + 397 + 2790 + 503

= (1210 + 2790) + (397 + 503)

= 4000 + 900

= 4900

397x18-18x254=(397-254)x18

                     =143x18

                     =2574

809x5-354x5=(809-354)x5

                    =455x5

                    =2275

   397 x 18 - 18 x 254                       809 x 5 - 354 x 5

= 18 x ( 397 - 254 )                      = 5 x ( 809 - 354 )

= 18 x    143                                 = 5 x   455

=    2574                                       =   2275

22344 x 36 + 44688 x 82

= 22344 x 36 + 22344 x 2 x 82

= 22344 x 36 + 22344 x 164

= 22344 x ( 36 + 164 )

= 22344 x 200

= 4468800

\(=82\times\left(10,5+3,2\right)+13,7\times18\)

\(=13,7\times82+18\times13,7\)

\(=13,7\times\left(18+82\right)\)

\(=13,7\times100=1370\)

=

= 82 x (10,5 + 3,2) + 13,7 x 18
= 82 x 13,7 + 13,7 x 18
= 13,7 x (82 + 18)
= 13,7 x 100
=1370

\(275\times15+825+82\times275\)

\(=275\times15+275\times3+82\times275\)

\(=275\times\left(15+3+82\right)\)

\(=275\times100\)

\(=27500\)

=275x15+82x275+825

=275x15+82x275+3x275

=275x(15+82+3)

=275x100

=275

\(=302\cdot100=30200\)

30200