a)  1 2 + 2 3 + 3 4 + 4 5 + 5 6 = 30 60 + 40 60 + 45 60 + 48 60 + 50 60 = 71 20

b)  4 6 + 27 81 = 4 6 + 2 6 = 1

a) 18 - 29 - 18 = -11 - 18 = -29

b) -17 - 34 - 17 = -51 - 17 = -68

c) 46 - 46 - 33 = 0 - 33 = -33

d) -77 - 23 - 567 - 77 = -100 - 567 - 77 = -667 - 77 = -744

Đúng thì cho 1 tick nha!

Giải:

( 12 + 77 + 34 + 23 + 88 + 45 + 55 + 66 ) . ( 45200 - 1808 .25 )

=( 12 + 77 + 34 + 23 + 88 + 45 + 55 + 66 ) . ( 45200 - 45200 )

=( 12 + 77 + 34 + 23 + 88 + 45 + 55 + 66 ) . 0

=0

Học tốt!!!

(12+77+34+23+88+45+55+66)* (45200-1808*25)

=(12+77+34+23+88+45+55+66)* (45200-45200)

=(12+17+34+23+88+45+55+66)* 0

=0

\(\left(12+77+34+23+88+45+55+66\right)\times\left(45200-1808\times25\right)\)

\(=\left(12+77+34+23+88+45+55+66\right)\times\left(45200-45200\right)\)

\(=\left(12+77+34+23+88+45+55+66\right)\times0\)

\(=0.\)

a. \(\dfrac{10}{21}>1\)

\(\dfrac{9}{23}< 1\)

\(\Rightarrow\dfrac{10}{21}>\dfrac{9}{23}\)

b. \(\dfrac{32}{33}>\dfrac{31}{33}>\dfrac{31}{34}\Rightarrow\dfrac{32}{33}>\dfrac{31}{34}\)

c. \(\dfrac{44}{47}< \dfrac{45}{47}< \dfrac{45}{46}\Rightarrow\dfrac{44}{47}< \dfrac{45}{46}\)

\(d.\dfrac{70}{117}< \dfrac{70}{115}=\dfrac{14}{23}\Rightarrow\dfrac{70}{117}< \dfrac{14}{23}< \dfrac{15}{23}\)

\(\Rightarrow\dfrac{70}{117}< \dfrac{15}{23}\)

Số 45 có 6 ước.

A) n = 2;3;4;7 

B) n = 4;8 

d) 24 ; 111 ; 333

12 x 23 = 276

34 x 46 = 1564

64 x 45 = 2880

12x23= 276

34x46=1564

64x45=2880

12*23=276

34*46=1564

64*45=2880

nhớ tk nha cảm ơn

12Al + 46HNO₃ --> 12Al(NO₃)₃ + 4NO + 3N₂O + 23H₂O

=> D

2Fe₃O₄ + 10H₂SO₄ --> 3Fe₂(SO₄)₃ + SO₂ + 10H₂O

=> B

bài 1 tính 
`a, 45 + 128 + 55 - 28 `

`=(45 +55)+(128-28)`

`=100+ 100`

`=200`
`b, 2022.194 - 2022.94 - 2200`

`=2022.(194-94)-2200`

`=2022.100-2200`

`=202200-2200`

`=200000`

`c, 2^3 .2 -3^4 :3^2`

`=2^(3+1) - 3^(4:2)`

`=2^4 - 3^2`

`=16-9`

`=7`

`d, 560 : { 130 - [( 5 . 14 - 65 ) . 3 + 3 ]}`

`= 560 : { 130 - [(70-65) . 3 + 3 ]}`

`= 560 : [ 130 - (5 . 3 + 3 )]`

`= 560 : [ 130 - (15+3) ]`

`= 560 :(130-18)`

`=560: 112`

`=5`

Số cần tìm là :

67+39+45+97+28+34+63-43+34+23+98-23-76=386

Đ/s : 386

Bằng 386 nha 

kqua la 386 ban nha 

k mk nhe