Question

Tính bằng cách thuận tiện nhất :
25x 125x4x8
789x5x2
123x125-24x123-123x30
415x98+415+415

ÉT O ÉT

Answer 1

a,=(25.4).(125.8)

=100.1000

=100000

b,=789.10=7890

c,123.(125-24-30)

=123.71

=8733

d,=415.(98+1+1)
=415.10

=4150

Answer 2

`25xx125xx4xx8=(25xx4)xx(125xx8)=100xx1000=100000`

`789xx5xx2=789xx(5xx2)=789xx10=7890`

`123xx125-24xx123-123xx30=123xx(125-24-30)=123xx71=8733`

`415xx98+415+415=415xx(98+1+1)=415xx100=41500`

Answer 3

 

25x 125x4x8
= (25x4) x 125 x 8 
 = 100 x 1000
= 100000 

789x5x2
= 789 x 10 
= 7890 

123x125-24x123-123x30
= (125 - 24 - 30 ) x 123
= 71 x 123 
= 8733

415x98+415+415 ​
=( 98 + 1 + 1)x  415
= 100 x 415
= 41500

 

 

 

Answer 4

123x 125 =125->154 nha

 

Answer 5

25 x 125 x 4 x 8

= (25 x 4) x (125 x 8)

= 100 x 1000

= 100 000

789 x 5 x 2

= 789 x (5 x 2)

= 789 x 10

= 7890

123 x 154 - 24 x 123 - 123 x 30

= 123 x (125 - 24 - 30)

= 123 x 100

= 12 300

415 x 98 + 415 + 415

= 415 x (98 + 1 + 1)

= 415 x 100 

= 41500