a) 96 + 78 + 4 = 96 + 4 + 78 = 100 + 78 = 178

67 + 21 + 79 = 67 + 100 = 167

408 + 85 + 92 = 405 + 92 + 85 = 500 + 85 = 585

b) 789 + 285 + 15 = 789 + 300 = 1089

448 + 594 + 52 = 448 + 52 + 594 = 500 + 594 = 1094

677 + 969 + 123 = 677 + 123 + 969 = 1769

a) 96 + 78 + 4 = 96 + 4 + 78 = 100 + 78 = 178

67 + 21 + 79 = 67 + 100 = 167

408 + 85 + 92 = 405 + 92 + 85 = 500 + 85 = 585

b) 789 + 285 + 15 = 789 + 300 = 1089

448 + 594 + 52 = 448 + 52 + 594 = 500 + 594 = 1094

677 + 969 + 123 = 677 + 123 + 969 = 1769

\(785+677+215+123=\left(785+215\right)+\left(677+123\right)=1000+800=1800\)

=(785+215)+(677+123)

=1000+800=1800

=(785+215)+(677+123)

=1000+800

=1800

=123x10=1230

\(=123\times\left(6+3+1\right)\)
\(=123\times10\)
\(=1230\)

\(123\times6+123+3\times123\\ =123\times\left(6+1+3\right)\\ =123\times10\\ =1230\)

`123 xx 137 - 123 xx 36 - 123`

`= 123 xx 137-123xx36-123xx1`

`=123xx(137-36-1)`

`=123xx100`

`=12300`

$#flo2k9$

`123 xx 137 - 123 xx 36 - 123`

= `123 xx ( 137 - 36 - 1 )`

= `123 xx 100`

= `12300`

\(123\times137-123\times36-123=123\times\left(137-36-1\right)=123\times100=12300\)

2785:123+2750:123

=(2785+2750):123

=5535:123

=45

Trl :

2 785 : 123 + 2 750 : 123

= ( 2 785 + 2 750 ) : 123

=          5 535          : 123

= 45

#Jun'z

~ HT ~

123 × 97 + 2 × 123 + 123 = 123 x ( 97 + 2 + 1) = 123 x 100 = 12300

123 x 97 + 2 x 123 + 123 

= 123 x 97 + 2 x 123 + 123 x 1 

=   123 x ( 97 + 2 +1 ) 

=  123 x 100 

=  12300.

                  N H Ớ   T I C K   C H O   M  Ì  N   H     N  H  A  

                             ~ HT~

123.75+123.24+123

=123.(75+24+1)

=123.100

=12300

 123 x 45 x 55 x 123 = 123 x ( 45 + 55 )

                               = 123 x       100

                               =           12300

có sai đề bài k?

 123 x 45 x 55 x 123 = 123 x ( 45 x 55 )

                                 = 304425