180360180

\(13\cdot42\cdot33\cdot26\cdot35\)

\(=\left(42\cdot35\right)\cdot\left(13\cdot26\right)\cdot33\)

\(=1470\cdot338\cdot33\)

\(=16396380\)

a,=3/13.17/29.29/34

=3/13.1/2

=3/26

b,=(4/21+25/42).19/33

=11/14.19/33

=19/42

`a, = 3/13 xx (17/29 xx 29/34)`

`= 3/13 xx 1/2`

`= 3/26`.

`b, = 19/33(4/21 + 25/42)`

`= 19/33 xx ( 33/42 )`

`= 19/42`

$\frac{3}{13}\times \frac{17}{29})\times \frac{29}{34}$

     $=\frac{3}{13}\times \frac{17}{29}\times \frac{29}{34}$

     $=\frac{3\times 17\times 29}{13\times 29\times 34}$

     $=\frac{3\times 17\times 29}{13\times 29\times 2\times 17}$

     $=\frac{3}{13\times 2}$

     $=\frac{3}{26}$

     $\frac{4}{21}\times \frac{19}{33}+\frac{25}{42}\times \frac{19}{33}$

     $=\frac{19}{33}\times (\frac{4}{21}+\frac{25}{42})$

     $=\frac{19}{33}\times (\frac{8}{42}+\frac{25}{42})$

     $=\frac{19}{33}\times \frac{33}{42}$

     $=\frac{19\times 33}{33\times 42}$

     $=\frac{19}{42}$

\(1235\text{×}6789\text{×}\left(630-315\text{×}2\right)\)

\(=1235\text{×}6789\text{×}\left(630-630\right)\)

\(=1235\text{×}6789\text{×}0=0\)

\(\left(100+67\right)\text{×}67+\left(200-38\right)\text{×}33\)

\(=167\text{×}67+167\text{×}33\)

\(=167\text{×}\left(67+33\right)\)

\(=167\text{×}100=16700\)

\(72+36\text{×}2+24\text{×}3+18\text{×}4+12\text{×}2+168\)

\(=72+72+72+72+24+168\)

\(=\left(72\text{×}4\right)+24+168=288+24+168=480\)

a) \(1235\times6789\times\left(630-630\right)\)

\(=1235\times6789\times0\)

\(=1235\times0\)

\(=0\)

b) \(167\times67+167\times33\)

\(=167\times\left(67+33\right)\)

\(=167\times100\)

=16700

11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99

= (11 + 88) + (22 + 77) + (33 + 66) + (44 + 55)  + 99

 =      99       +       99      +      99        +      99       + 99

= 99 x 5

= 495

11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99

= (11 + 99) + (22 + 88) + (33 + 77) + (44 + 66) + 55

=      110     +      110     +     110      +     110      + 55

= 495

11 + 22 + 33 + 44 + 55 + 66 + 77 + 88 + 99

= (11 + 99) + (22 + 88) + (33 + 77) + (44 + 66) + 55

= 110 +  110 +110 + 110 + 55

= 495