=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`

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

123 x 54 + 123 x 46

= 123 x (54 +46) = 123 x 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

12,3 x 6 + 123 x 0,1 + 1,23 x 50 - 24,6

= 12,3 x 6 + 12,3 + 12,3 x 5 - 12,3 x 2

= 12,3 x (6 + 1 + 5 - 2)

= 12,3 x 10

= 123

123×45+123×55

=123×(45+55)

=123×100

=12300

56×4+56×3+56×2+56

=56×4+56×3+56×2+56×1

=56×(4+3+2+1)

=56×10

=560

[ 123×154-65×123]:89

=[123×(154-65)]:89

= 123×89:89

=123×(89:89)

=123×1

=123

123 x 45 + 123 x 55

= 123 x ( 45 + 55 )

= 123 x 100

= 12300

56 x 4 + 56 x 3 + 56 x 2 + 56

= 56 x ( 4 + 3 + 2 + 1 ) 

= 56 x 10

= 560

[ 123 x 154 - 65 x 123 ] : 89

= [ 123 x ( 154 - 65 ) ] : 89

= [ 123 x 89 ] : 89

= 123

Học tốt #

123 x 45 + 123 x 55

= 123 x ( 45 + 55 )

= 123 x 100

= 12300

56 x 4 + 56 x 3 + 56 x 2 + 56

= 56 x ( 4 + 3 + 2 + 1 )

= 56 x 10

= 560

[123 x 154 - 65 x 123] : 89

= [ 123 x ( 154 - 65 ) ] : 89

= [ 123 x 89 ] : 89

= 123 x 89 : 89

= 123

Tính bằng cách thuận tiện :

 37 x 68 + 123 x 74

= 37 x 68 + 123 x 2 x 37

= 37 x 68 + 246 x 37

= 37 x ( 246 + 68 )

= 37 x 314

= 11618

37 x 68 + 123 x 74 

= 37 x 68 + 123 x 2 x 37 

= 37 x 68 + 37 x 246 

= 37 x ( 68 + 246 ) 

= 37 x 314 

= 11618 

37 x 68 + 123 x 74 

= 37 x 2 x 34 + 123 x 74 

= 74 x 34 + 123 x 74

= 74 x ( 34 + 123 ) 

= 74 x  157

= 11618

Chúc bạn học tốt !!! 

\(=\dfrac{1}{2}\cdot\dfrac{2}{3}\cdot\dfrac{6}{5}\cdot\dfrac{5}{6}=\dfrac{1}{2}\cdot\dfrac{2}{3}=\dfrac{1}{3}\)

\(\dfrac{1}{2}\times\dfrac{2}{3}:\dfrac{5}{6}\times\dfrac{5}{6}\)

\(=\dfrac{1}{2}\times\left(\dfrac{2}{3}:\dfrac{5}{6}\times\dfrac{5}{6}\right)\)

\(=\dfrac{1}{2}\times\dfrac{2}{3}\)

\(=\dfrac{1}{3}\)

2/

a)\(\dfrac{1}{5}+\dfrac{4}{5}+\dfrac{4}{11}+\dfrac{7}{11}\)

= \(\dfrac{5}{5}+\dfrac{11}{11}\)

= \(1+1\)

= \(2\)

b) \(\left(\dfrac{1}{8}+\dfrac{3}{8}\right)+\left(\dfrac{4}{12}+\dfrac{5}{12}\right)\)

= \(\dfrac{4}{8}+\dfrac{8}{12}\)

= \(\dfrac{12}{24}+\dfrac{16}{24}\)

= \(\dfrac{28}{24}\)

= \(\dfrac{7}{6}\)

=1 + (1/2×5/2×3/2)+2/3

=1 + 15/8 + 2/3

=1 + 61/24

=85/24