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: Ta có: 24+35+76+65+22

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

=222

b: Sửa đề: \(24\cdot35+24\cdot65\)

=24x100

=2400

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) \(\left(81+19\right)+35=135\)

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

25 . 35 + 24 . 65

= 875 + 1560

= 2435

b: \(24\cdot35+24\cdot65\)

=24x100

=2400

a: =100x26=2600

b: =78x10=780

c: =67x100=6700

d: =1000x575=575000

\(4\times26\times25=\left(4\times25\right)\times26=100\times26=2600\\ 63\times78-53\times78=\left(63-53\right)\times78=10\times78=780\\ 67\times92+67\times8=67\times\left(92+8\right)=67\times100=6700\\ 8\times23\times25\times125=\left(8\times125\right)\times\left(23\times25\right)=1000\times575=57500\)

a: =100x26=2600

b: =78x10=780

c: =67x100=6700

d: =1000x575=575000

Trả lời :

20 + 21 + 22 + 23 + 24 + 25 + 26 + 27 = 188

~ Học tốt ~

Gộp lại thôi

456 x 65 + 456 x 25 + 456 x 10

=456x(65+25+10)

=456x100

=45 600

21+22+23+24+25+26+9+8+7+6+5+4 =180

mình thấy rồng con lon ton làm đúng đấy

21 + 22 + 23 + 24 + 25 + 26 + 9 + 8 + 7 + 6 + 5 + 4

= (21 + 9) + (22 + 8) + (23 + 7) + (24 + 6) + (25 + 5) + (26 + 4)

= 30 + 30 + 30 + 30 + 30 + 30

= 30 x 6

= 180

bạn lấy 21+9+22+8+23+7+24+6+25+5+26+4=30+30+30+30+30+30=180