1: therefore

2 : would

Gọi số điểm tốt của các tổ 1;2;3;4 lần lượt là a;b;c;d

Từ đề => a/5 = b/6 = c/7 = d/9 và d - a = 9

Áp dụng tính chất dãy tỉ số bằng nhau ta có:

\(\frac{a}{5}=\frac{b}{6}=\frac{c}{7}=\frac{d}{8}=\frac{d-a}{8-5}=\frac{9}{3}=3\)

Số điểm tốt tổ 1 đạt được là: 3 x 5 = 15 điểm

Số điểm tốt tổ 2 đạt được là: 3 x 6 = 18 điểm

Số điểm tốt tổ 3 đạt được là: 3 x 7 = 21 điểm

Số điểm tốt tổ 4 đạt được là: 3 x 8 = 24 điểm

b

a)     So với số dân năm 2000 thì số dân của năm 2001 bằng:

                                   15 875 : 15 625 = 1,016 = 101,6%

Số dân của phường đó đã tăng thêm:

                                101,6% - 100% = 1,6%

b)    1,6% của 15 875 người là:

                          15875 x 1,6 : 100 = 254 (người)

Số dẫn của phường đó năm 2002 là:

          15875 + 254 = 16 129 (người)

                  Đáp số a) 1,6 người

                              b)  16129 người

Well, here I am in England. Thank you for your (1) kind/kindly letter.

You ask me what it's like here. I must say, it's pretty (2) good/well. The language school is very (3) efficient/efficiently organized. On the first morning we had to do a test, which I found rather (4) hard/hardly. However I got a (5) surprising/surprisingly good mark, so I'm in the second class. I didn't talk much at first, because I couldn't think of the worlds (6) quick/quickly enough, but (7) late/lately I've become much more (8) fluent/fluently. I'm staying with a family who live (9) near/nearly the school. They are quite (10) pleasant/pleasantly, although I don't see much of them because I'm always so (11) busy/busily with my friends from school. I was surprised how (12) easy/easily I made new friends here. They come from (13) different/differently parts of the world and we have some (14) absolute/absolutely fascinating discussions. I do hope you will be able to join me here next term. I'm sure we'd have (15) good/well fun together.

Put the words in brackets into the right form to complete the sentences.

1. I like cooking in my free time. It makes me feel ___relaxed___. (relax)

2. My sister doesn't like surfing the Internet, she says it is ____boring_____ (bore)

3. My close friend gave me __wonderful _____ present pn my birthday. I like it so much. (wonder)

4. My brother work as the volunteer for an animal protection ___organism_____. He really love his job. (organize)

Nêu những việc nên làm để giữ vệ sinh cơ thể ở tuổi dậy thì

Ta có:  

\(\left(a+b+c\right)\left(\frac{a}{b+c}+\frac{b}{c+a}+\frac{c}{a+b}\right)=a+b+c\) (Do  \(\frac{a}{b+c}+\frac{b}{c+a}+\frac{c}{a+b}=1\) )

\(\Leftrightarrow\frac{a^2}{b+c}+a+\frac{b^2}{c+a}+b+\frac{c^2}{a+b}+c=a+b+c\)

\(\Leftrightarrow\frac{a^2}{b+c}+\frac{b^2}{c+a}+\frac{c^2}{a+b}=a+b+c-\left(a+b+c\right)=0\left(đpcm\right)\)

*Lưu ý: Có rút gọn một số bước. 

1."We went swimming today"

-> They said they had gone swimming that day.

2."I'll meet Mary on Sunday"

-> She said she would meet Mary on Sunday.

3."I really like this furniture"

-> He said he really liked that furniture.

4."I'm meeting them at four o' clock today"

-> He said he was meeting them at four o'clock that day.

5."I live here with my parents"

-> She said she lived there with her parents.

6."Our new house is beautiful"

-> They said their new house was beautiful.

7."I want to be a teacher of English"

-> She said she wanted to be a teacher of English.

8."I can't speak chinese"

-> He said he couldn't speak Chinese.

9."My sister is now having a wonderful time in Nha Trang"

-> She said her sister was then having a wonderful time in Nha Trang.

10."I'll be very busy today"

-> He said he would be very busy that day.

11."I must come to the meeting tomorrow"

-> He said he had to come to the meeting the next day.

12."These roses are for you"

-> He said these roses were for her.

13."I'm going away tomorrow, mother"

-> I said to my mother I was going away the next day.