1. 202557-two zero two double five seven

2. 777390-...double seven three nine zero.............................................

3. 224469-..double two double four six nine..............................................

4. 638904-.six three eight nine zero four..............................................

5. 222555-..double two two double five five.............................................

6. 660072-.double six double zero seven two.............................................

tick cho mk nha bạn

1. 202557  -  two zero two double five seven

2. 777390  -  double seven three nine zero

3. 224469  -  double two double four six nine

4. 638904  -  six three eight nine zero four

5. 222555  -  double two two double five five

6. 660072  -  double six double zero seven two

1.seventy five - thirty seven = 75 - 37 = 38

2.thirteen + seven = 13 + 7 = 20

3.six x nine = 6 x 9 = 36

4.sixty five + fourteen = 65 + 14 = 79

5.twelve x five = 12 x 5 = 60

6.eighty - twelventy three = 80 - 23 = 57

7.fourty five + nine = 45 + 9 = 54

8.ninety six - fifty two = 96 - 52 = 44

9.sixty nine : three = 69 : 3 = 23

10.thirty fine + nine= 35 + 9 = 44

1. They have a cold. (have) 

2. She gets up at seven. (get up) 

3. We have breakfast at eight. (have)

4. Peter goes to school. (go)

5. Anna gets home at two. (get)

6. He wants an ice cream. (want)

7. I hate peppermint. (hate)

8. Kelly watches TV. (watch)

9. She does her homework. (do)

10. Our teacher lives in Oxford Street. (live)

11. Eric and Tom wear blue shirts. (wear)

12. My sister sings a song. (sing)

13. My mum cooks spaghetti. (cook)

14. Mr Black works  in his office. (work)

15. The girls often reads a book. (read)

1 are having

2 gets up

3 have

4 is going

5 gets

6 wants

7 hate

8 is watching

9 is doing

10 lives

11 are wearing

12 is singing

13 is cooking

14 is working

15 read

a, 5ⁿ⁺¹ - 5^n-1 = 125⁴.2³.3

5^n-1.(5² - 1) = 125⁴.24

5^n-1.24         = 125⁴.24

5^n-1             = 125⁴

5^n-1             = (5³)⁴

5^n-1            = 5¹²

n - 1           = 12

n                = 12 + 1

n                = 13

b,2^2n-1 + 2²ⁿ⁺² = 3.2¹¹

   2^2n-1.(1 + 2³) = 3.2¹¹

  2^2n-1.9 = 3.2¹¹

 2^2n-1      = 2¹¹: 3

2²ⁿ        = 2¹² : 3 (xem lại đề bài em nhá)

1/2.2 + 1/3.3 + 1/4.4 + ... + 1/9.9

> 1/2.3 + 1/3.4 + 1/4.5 + ... + 1/9.10

> 1/2 - 1/3 + 1/3 - 1/4 + 1/4 - 1/5 + ... + 1/9 - 1/10

> 1/2 - 1/10

> 5/10 - 1/10

> 2/5 (1)

1/2.2 + 1/3.3 + 1/4.4 + ... + 1/9.9

< 1/1.2 + 1/2.3 + 1/3.4 + ... + 1/8.9

< 1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + ... + 1/8 - 1/9

< 1 - 1/9

< 8/9 (2)

Từ (1) và (2) => 2/5 < 1/2.2 + 1/3.3 + 1/4.4 + ... + 1/9.9 < 8/9

\(\dfrac{3.3}{20.23}+\dfrac{3.3}{23.26}+...+\dfrac{3.3}{77.80}\)

\(=3\left(\dfrac{3}{20.23}+\dfrac{3}{23.26}+...+\dfrac{3}{77.80}\right)\)

\(=3\left(\dfrac{1}{20}-\dfrac{1}{23}+\dfrac{1}{23}-\dfrac{1}{26}+...+\dfrac{1}{77}-\dfrac{1}{80}\right)\)

\(=3\left(\dfrac{1}{20}-\dfrac{1}{80}\right)\)

\(=3.\dfrac{3}{80}=\dfrac{9}{80}< 1\left(đpcm\right)\)

Vậy...

rất là hay

1 My grandfather is eighty-two so he is quite old now

2 My grandmother is sixty-seven and she is much younger than my grandfather

3 They are living in an apartment on the second floor of a big building

4 Their living room is large and there is very old furniture in it

5 The small bedroom is the place where I sleep when I stay with them