Gọi số cần tìm là abcde ( e chẵn và các chữ số khác nhau từng đôi một )
TH1 : e = 0
Chọn e : 1 cách
Chọn a :5 cách
chọn b :4 cách
chọn c :3 cách
chọn d :2 cách
=> Theo Quy tắc nhân có : 1.5.4.3.2 = 120 .
TH2 : e # 0
Chọn e :2 cách
Chọn a :4 cách
chọn b :4 cách
chọn c :3 cách
chọn d :2 cách
=> Theo quy tắc nhân có :2.4.4.3.2 = 192
=> Có tất cả 192 +120 =312 số chẵn có 5 chữ số khác nhau
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\(3cot\left(x-\frac{\pi}{3}\right)=\sqrt{3}\)
<=> \(cot\left(x-\frac{\pi}{3}\right)=\frac{\sqrt{3}}{3}\)
<=> \(x-\frac{\pi}{3}=\frac{\pi}{3}+k.\pi\)
<=> x = π/6 + kπ (k là số nguyên )

Over 5000 people work in the United States's Library of Congress
=> How many people work in the United States's Library of Congress

The police said to me : "can you stop"
=> The police told me to stop

\(=\left(4\times2^5\right):\left(\frac{8.1}{16}\right)=128:\frac{1}{2}=256\)

1. Linh/ not enough / stay/ to / alone/ old / isn't/ at home
=> Linh isn't old enough to stay alone at home.
2. They/ are/ have / to/ on/ going/ meeting/ Thursday/ a
=> They are going to have a meeting on Thursday

1. I could hold a big party due to my Mom's help.
=> Had it not been for my Mom's help, I couldn't have held a big party
2. What you do with the money is of no interest to me.
=> I don't care what you will do with money
3. I feel uncomfortable to be in a room where everybody is shouting.
=>I can't stand being in a room where everyboby is shouting
4. The Picasso painting was so expensive that nobody could buy it.
=> So expensive was the Picasso painting that nobody could buy it.
 

since + mốc thời gian .vd :1950,2016..
For + Khoảng thời gian vd.. 3 tháng, 4 tháng.. v..vv

Taa co : a:b:c:d=7:6:5:4 va a+b+c+d=66

\(a:b:c:d=7:6:5:4=\frac{a}{7}=\frac{b}{6}=\frac{c}{5}=\frac{d}{4}\)

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

\(\frac{a}{7}=\frac{b}{6}=\frac{c}{5}=\frac{d}{4}=\frac{a+b+c+d}{7+6+5+4}=\frac{66}{22}=3\)

Suy ra : \(\frac{a}{7}=3\Rightarrow a=3.7=21\)

\(\frac{b}{6}=3\Rightarrow b=3.6=18\)

\(\frac{c}{5}=3\Rightarrow c=3.5=15\)

\(\frac{d}{4}=3\Rightarrow d=3.4=12\)

1. The table and the desk are the same size. (big)
=> The table is as big as the desk
2. Clair and her sister intend to spend summer holidays in Bali. (going)
=> Clair and her sister are going to spend summer holidays in Balin.
3. Could you tell me the way to the Oxford Street , please? (mind)
=> Do you mind showing me the way to the Oxford Street

4. Martin to Susan: Can you work on Saturdays? (asked)
=> Martin asked Susan if she could work on Saturdays
5. When I was young , I regularly travel around the country. (used)
=> I used to travel around the country when I was young

6. His boddy is to collect stamps .(fond)
=>He is fond of collecting stamps

7. Etienne Lenoir made the first motor car.(by)
=> The first motor car was made by Etienne Lenoir.
8. Anna to Mike : Would you like to join me for lunch? (invited)
=> Anna invited Mike to join her for lunch.

9. Everyone agreed that the plan should go ahead. (it)
=> It was agreed that the plan should go ahead.

10. People say exercise is good for you. (be)
=> Exercise is said to be good for you