123 x 54 + 123 x 46

= 123 x (54 +46) = 123 x 100

= 12300

a) 19,17x25x4=19,17(25x4)=19,17x100=1917

b)1,79x(8x125)=1,79x1000=1790

chúc bạn học tốt

 215 x 123 - 125 x 23

= 123 x ( 215 - 125 )

= 123 x 90

= 123 x 9 x 10

= 1230 x 9

= 11070

Cấm ai k

 215 x 123 - 125 x 23

= 215 x 123 - 125 x 123 - 125 x 100

= 123 x ( 215 - 125 ) - 125 x 100

= 123 x 90 - 125 x 100

= 11070 - 12500

= -1430

215 x 123 - 125 x 23

= 215 x 23 - 125 x 23 + 215 x 100

= 23 x ( 215 - 125 ) + 21500

= 23 x 90 + 21500

= 2070 + 21500

= 23570

Ta có :A)

 \(=123\cdot0,1\cdot4+123\cdot0,1+123\cdot0,01\cdot50\)

\(=123\cdot\left(4\cdot0,1+0,1+0,01\cdot50\right)\)

\(=123\cdot\left(0,4+0,1+0,5\right)\)

\(=123\cdot1\)

\(=123\)

Bn ơi chấm là j, dấu chấm á

\(a,123\times54+27\times123-12\times123+123\times31\)

\(=123\times\left(54+27-12+31\right)\)

\(=123\times100\)

\(=12300\)

\(b,\dfrac{121}{27}\times\dfrac{54}{11}< n< \dfrac{100}{21}:\dfrac{25}{126}\)

\(22< n< \dfrac{100}{21}\times\dfrac{126}{25}\)

\(22< n< 24\)

Vì \(23>22\) và \(23< 24\) nên \(n=23\)

a, 123x(54+27-12+31)

=123x100

=12300

a123x54+27x123-12x123+123x31

=123:54+27:123-12:123+123:31

=6642+27:123-12:123+123:31

=6642+3321-12:123+123:31

=6642+3321-1476+123:31

=6642+3321-1476+3813

=12300

b,121/27x54/11<n>100/21:25/126

=22<n>24

n=23

=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`

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

(123x5+238)x(40-8x5)

=(123x5+238)x(40-40)

=(123x5+238)x0

=0

(123 x 5 + 238) x (40 - 8 x 5)

= (123 x 5 + 238) x (40 - 40)

= (123 x 5 + 238) x 0

= 0

(123 x 5 + 238) x (40 - 8 x 5)

= (123 x 5 + 238) x (40 - 40)

= (123 x 5 + 238) x 0

= 0