`@` `\text {Ans}`

`\downarrow`

`a)`

`20 \times 6 \times 5 \times 7`

`= (6 \times 7) \times (20 \times 5)`

`= 42 \times 100`

`= 4200`

`b)`

`125 \times 789 \times 8`

`= (125 \times 8) \times 789`

`= 1000 \times 789`

`= 789000`

`c)`

`2 \times 3 \times 4 \times 8 \times 50 \times 25 \times 125`

`= (2 \times 50) \times 3 \times (4 \times 25) \times (8 \times 125)`

`= 100 \times 3 \times 100 \times 1000`

`= 300000000`

a) 20 x 6 x 5 x 7

= ( 20 x 5 ) x ( 6 x 7 )

= 100 x 42

= 4200

\(1125:25+1375:1000:40\)

\(=1125:25+1375:25\)

\(=\left(1125+1375\right):25\)

\(=2500:25\)

\(=100\)

\(\text{6,48 × 1125 - 6,48 × 112 - 6,48 × 13 }=6,48\times\left(1125-112-13\right)=6,48\times1000=6480\)

= 6,48 x ( 1125 - 112 - 13 )

= 6,48 x 1000

= 6480
 

  789 x 101 - 789

   789 x 101 - 789 x 1

= 789 x ( 101 - 1 ) 

= 789 x  100

= 78900

Học vui nha !

^^

789x101-789=789x101-789x1=789x(101-1)=789x100=78900

789 x 62 - 789 x 8 + 37 x 789 + 789

= 789 x ( 62 - 8 + 37 + 1 )

= 789 x 92

= 72588

~~Cô gái xử nữ~~

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

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

chúc bạn học tốt

\(=789:789.101\)

\(=1.101\)

\(=101\)

. là dấu nhân

789 x 101 : 789

=(789 : 789) x 101

=       1         x 101

= 101

=(290+590)+(789+31)

=880+820

=1900

= (789 + 31) + 290 + 590

= 810 + 290 + 590

= (810 + 290) + 590

= 1100 + 590

= ?

=50:5.19

=10.19

=190

b) =125.(48:6)
=125.8

=1000

 A=(50*19):5=(50:5)*(19:5)=10*3,8=38                                                                                                                                                  B(125*48):6=(125:6)*(48:6)=20/5/6*6=166/2/3