154 x 35 + 154 x 65 = 154 x (35 + 65)  

= 154 x 100  = 15400

= 35*(20,10-19,45)+65*(20,10-19,45)

=35*0,65+65*0,65

=0,65*(35+65)

=0,65*100

=65

 35 × 34 + 34 × 38 + 65 × 75 + 65 × 45

= 34 × (35 + 38) + 65 × (75 + 45)

= 34 × 73 + 65 × 120

= 2482 + 7800

= 10282

~Study well~

#KSJ

35 x 34 + 34 x 38 + 65 x 75 + 65 x 45

= (35 x 34 + 34 x 38) + (65 x 75 + 65 x 45)

= 34 x (35 + 38) + 65 x (75 + 45)

= 34 x 73 + 65 x 120

= 2482 + 7800

= 10282

35 x 34 + 34 x 38 + 65 x 75 + 65 x 45

= (35+38 ) x34 + 65 x ( 75 + 45 )

= 73x 34 + 65 x 120

=2482 + 7800

=10282

học tốt nhớ k cho mình nhé

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

= 100 + 35

= 135

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

= 100 + 200

= 300

a) 81+35+19

=80+30+(1+9)+5

=110+10+5

=120+5

=125

b) 78+65+135+22

=70+60+130+20+(8+2)+(5+5)

=280+10+10

=300

a) 234 + 567 + 766 + 433

= (234 + 766) + (567 + 433)

= 1 000 + 1 000

= 2 000

b) 2 023 + 7 602 - 1 023 + 1 398

= (2 023 - 1 023) + (7 602 + 1 398)

= 1 000 + 9 000

= 10 000

c) 4 789 - 2 567 - 7 433 + 5 211

= (4 789 + 5 211) - (2 567 + 7 433)

= 10 000 - 10 000

= 0

c, 5 - 10 + 15 - 20 + 25 - 30 + 35 - 40 + 50 - 55 + 60 - 65 + 70

= 5 + (15 - 10) + (25 - 20) + (35 - 30) + (50 - 40) + (60 - 55) + (70 - 65)

= 5 + 5 + 5 + 5 + 10 + 5 + 5

= (5 + 5) + (5 + 5) + 10 + (5 + 5)

= 10 + 10 + 10 + 10

= 10 $\times$ 4

= 40

a,   234 + 567 + 766 + 433

= (234 + 766) + (567 + 433)

= 1000 + 1000

= 2000

b, 2023 + 7602 - 1023 + 1398

= (2023 - 1023) + (7602 + 1398)

= 1000 + 9000

= 10000

c, 4789 - 2567 - 7433 + 5211

= (4789 + 5211) - (2567 + 7433)

= 10000 - 10000

= 0

d, 5 - 10 + 15  - 20 + 25 - 30 + 35 - 40 + 50 - 55 + 60 - 65 + 70

= (70 -65) + (60 - 55) +(50 - 40) + (35  - 30) + (25 - 20) + (15 - 10) + 5

= 5 + 5 + 10 + 5 + 5  + 5  + 5

= 5 x 6 + 10

= 40 

a) 2000

b) 0

c) 40

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
=(65+35)+(76+22)+25
=100+100+25
=225
c , 78-23-25
=78-(23+25)
=78-48
=30
a , x-45=20 
x=20+45
x=65
b , 45 - x=20
     x =45-20
     x= 25

Bài 2: 

a: Ta có: x-45=20

nên x=65

b: Ta có: 45-x=20

nên x=25

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) \(\left(81+19\right)+35=135\)

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