a) \(\left(81+19\right)+35=135\)

b) \(\left(78+22\right)+\left(65+135\right)=100+200=300\)

c) \(\left(234+17716\right)+23=17950+23=17973\)

d) \(\left(99+1\right)+85=100+85=185\)

\(a,81+35+19=\left(81+19\right)+35=100+35=135\\ b,78+65+135+22=\left(78+22\right)+\left(65+135\right)=100+200=300\\ c,234+17716+23=\left(234+17716\right)+23=17950+23=17973\\ d,85+99+1=85+\left(99+1\right)=85+100=185\)

A) 81+ 19 +35

=100+35=135

B) 78+65+135+22

=78+22+65+135

100+200=300 

mấy câu cx làm tương tự

dài quá  ko thích tính

tính bằng cách thuận tiện nhất

34000 + 57859 + 66000

= (34000 + 66000) + 57859

= 100000 + 57859 

= 157859

8973 + 45783 + 46027 + 54217

= (8973 + 46027) + (45783 + 54217)

= 55000 + 100000

= 155000

78 + 65 + 135 + 22

= (78+ 22) + (65 + 135)

= 100 + 200

= 300

`@34000 + 57859 + 66000`

`=( 34000 + 66000 ) + 57859`

`= 100000 + 57859`

`=157859`

_____________________________

`@ 8973 + 45783 + 46027 + 54217`

`= ( 8973 + 46027 ) + ( 45783 + 54217 )`

`= 55000 + 100000`

`=155000`

___________________________________

`@78 + 65 + 135 + 22`

`= ( 78 + 22 ) + ( 65 + 135 )`

`= 100 + 200`

`= 300`

a: Ta có: 24+35+76+65+22

=(24+76)+(35+65)+22

=222

b: Sửa đề: \(24\cdot35+24\cdot65\)

=24x100

=2400

Cái gì khó có gg ok

a)   175× 582-25 ×582

= ( 175 - 25 ) x 582

= 150 x 582

= 87300

b)   81 × 365 + 18 ×365 +365

=  81 × 365 + 18 × 365 + 365 x 1

= ( 81 + 18 + 1 ) x 365

= 100 x 365

= 36500

a) \(175\times582-25\times582\)

\(=582\times\left(175-25\right)\)

\(=582\times150\)

\(=87300\)

b) \(81\times365+18\times365+365\)

\(=81\times365+18\times365+365\times1\)

\(=365\times\left(81+19+1\right)\)

\(=365\times100=36500\)

a) 4 x 78 x 5

= (4 x 5) x 78

= 20 x 78

= 1560

b) 2 x 99 x 5

= (2 x 5) x 99

= 10 x 99

= 990

\(7,\)

\(a,=\left(4\times5\right)\times78=20\times78=1560\)

\(b,=\left(2\times5\right)\times99=10\times99=990\)

a. 4 x 78 x 5 = 4 x 5 x 78 = 20 x 78 = 1560

b. 2 x 99 x 5 = 2 x 5 x 99 = 10 x 99 = 990

b, 53 + 45 + 135 + 147 + 50

= ( 53 + 147 ) + ( 45 + 135 ) + 50

= 200 + 180 + 50

= 200 + 330

= 530

b, 53 + 45 + 135 + 147 + 50

=(53+147)+(45+135+50)

=200+230

=430

a , 25 + 35 + 76 +65 + 22
= 25+(35+65)+(76+22)
=25+100+100
=225

b , 24 + 25  + 24 x 22
=24(1+22)+25
=552+25
=577

c , 78 - 23 - 25
=78-(23+25)
=78-48
=30

a: \(25+35+76+65+22\)

\(=\left(25+75\right)+\left(35+65\right)+23\)

=223

c: Ta có: 78-23-25

=78-48

=30

a = (81+19)+35

=100+35=135

b = (78+22)+(65+135)

=100+200=300

c = (234+17716)+23

=17950+23=17973

d = (99+1)+85

=100+85=185

a) 81 + 35 + 19 = (81 + 19) + 35 = 100 + 35 = 135

b) 78 + 65 + 135 + 22 = (78 + 22) + (135 + 65) = 100 + 200 = 300

c) 234 + 17716 + 23 = 17950 + 23 = 17973

d) 85 + 99 + 1 = 85+ (99 + 1) = 85 + 100 = 185

\(a,=116+19=135\\ b,=143+135+22\\ =278+22=300\\ c,=17950+23=17973\\ d,=184+1=185\)