câu a =3000

a, 28(231+69)+72(231+69)                  

=231+69.(28+72)

=231+69.100

=231+6900

=7131

b, 39(250+87)+64(240+97)

=39.337+64.337

=337(39+64)

=337.103

=34711

a) \(28.\left(231+69\right)+72.\left(169+31\right)=28.300+72.200\)

\(=100.\left(28.3+72.2\right)=100.\left(84+144\right)=100.228=22800\)

b) \(39.\left(250+87\right)+61\left(240+97\right)=39.337+61.337\)

\(=337.\left(39+61\right)=337.100=33700\)

   28  .  ( 231  +  69 )  +  72  .  ( 231  +  69 )

= ( 231  +  69 )  .  ( 72  +  28 )

= 300  .  100

= 30000

=28.231+28.69+72.231+72.69

=28.231+72.231+28.69+72.69

=231.(72+28)+69.(28+72)

=231.100+69.100

=32100+6900

=39000

28+72.(213+69)=100.282=28200

\(=30000\)

đúng thì k nha

  28.(231 + 69) +72. (231 + 69 )

=28.   300       +72.     300

= 300.(28+72)

= 300.  100

=30000

KB nha!!!

28.(231+69)+72.(231+69)=

28.231+28.69+72.231+72.69=

(28+72).231+(28+72).69=

100.231+100.69=

100.(231+69)=

100.300=30000

1) 12.2.25+29.25+59.25

=24.25+29.25+59.25

=25(24+29+59)

=25.112

=2800

2) 25.(231+69)+72.(231+69)

=25.300+72.300

=300(25+72)

=300.97

=29100

3) 39.(250+87)+64.(240+97)

=39.337+64.337

=337.(39+64)

=337.103

=34711

4) 36.28+36.82+64.69+64.41

=36.(28+82)+64.(69+41)

=36.110+64.110

=110(36+64)

=110.100

=11000

Đăng từng bài thôi nha bạn.

12 x 2 x 25 + 29 x 25 + 59 x 25 = 2800

25 x  ( 231 + 69 ) + 72 x ( 231 + 69 ) = 29100

39 x ( 250 + 87 ) + 64 x ( 240 + 97 ) = 34711

 36 x 28 + 36 x 82 + 64 x 69 + 64 x 41 = 11000

Cho mik xin đúng nhá

1) 12 x 2 x 25 + 29 x 25 + 59 x 25

= 24 x 25 + 29 x 25 + 59 x 25

= 25 x ( 24 + 29 + 59 )

= 25 x 112

= 2800

2) 25 x ( 231 + 69 ) + 72 x ( 231 + 69 )

= 25 x 300 + 72 x 300

= ( 25 + 72 ) x 300 

= 29100

3)39 x ( 250 + 87 ) + 64 x ( 240 + 97 )

= 39 x 337 + 64 x 337

= ( 39 + 64 ) x 337

= 103 x 337

= 34711

tính nhanh 

1) 12.2.25+29.25+59.25

2) 25.(231+69)+72.(231+69)

3) 39.(250+87)+64.(240+97)

4) 36.28+36.82+64.69+64.41

1) 12 x 2 x 25 + 29 x 25 + 59 x 25

= 24 x 25 + 29 x 25 + 59 x 25

= 25 x ( 24 + 29 + 59 )

= 25 x 112

= 2800

2) 25 x ( 231 + 69 ) + 72 x ( 231 + 69 )

= 25 x 300 + 72 x 300

= ( 25 + 72 ) x 300 

= 29100

3)39 x ( 250 + 87 ) + 64 x ( 240 + 97 )

= 39 x 337 + 64 x 337

= ( 39 + 64 ) x 337

= 103 x 337

= 34711

1) 12 x 2 x 25 + 29 x 25 + 59 x 25

= 24 x 25 + 29 x 25 + 59 x 25

= 25 x ( 24 + 29 + 59 )

= 25 x 112

= 2800

2) 25 x ( 231 + 69 ) + 72 x ( 231 + 69 )

= 25 x 300 + 72 x 300

= ( 25 + 72 ) x 300 

= 29100

3)39 x ( 250 + 87 ) + 64 x ( 240 + 97 )

= 39 x 337 + 64 x 337

= ( 39 + 64 ) x 337

= 103 x 337

= 34711

Tính nhanh  

28.(231+69) +72(231+69)

= 28 x 300 + 72 x 300

= (28+72) x 300

= 100 x 300

= 30000

#Học tốt!

Chúc bn ngày mới vui vẻ!

Hình như đề là: 28.(231+69)+72.(231+69)

=28.231+28.69+72.231+72.69

=231(28+72)+69(28+72)

=100.231+100.69

=100(231+69)

=100.300=30000

28.(231+69) + 72.(321+69)

= 28.300 + 72.300 + 72.90

= 300.(28+72) + 72.9.10

= 300.100 + 648.10

= 30000+ 6480

= 39480

=28.231+28.69+72.321+72.69

=321.(72+28)+69.(72+28)

=321.100+100.69

=100.(321+69)

=100.390=39000

chúc bạn học tốt