Đa thức f(x) =ax^3+bx^2+cx+d chia hết cho đa thức x-1 với a+b+c+d=0

cho số n nguyên dương và các tổng sau:

S\(_1\)=1+\(\dfrac{1}{5}\), S\(_2\)=1+\(\dfrac{1}{5}+\dfrac{1}{5^2}\), S\(_3\)=1+\(\dfrac{1}{5}+\dfrac{1}{5^2}+\dfrac{1}{5^3}\), S\(_n\)=1+\(\dfrac{1}{5}+\dfrac{1}{5^2}+\dfrac{1}{5^3}+........+\dfrac{1}{5^n}\)

Chứng minh rằng: \(\dfrac{1}{5S_1^2}+\dfrac{1}{5^2S_2^2}+\dfrac{1}{5^3S^2_3}+.....+\dfrac{1}{5^nS^2_n}< \dfrac{35}{36}\)

tìm n sao cho

\(\dfrac{2\sqrt{n}-1}{\sqrt{n}-4}\)là số tự nhiên

cho x,y,t,z thuộc N*

chứng minh M=\(\dfrac{x}{x+y+z}+\dfrac{y}{x+y+t}+\dfrac{z}{y+z+t}+\dfrac{t}{x+z+t}\)có giá trị ko phải số tự nhiên

Put the verbs in brackets into the present simple or presen continuous

1. A:I see you still have a toothache

B:Yes,I do.Actually,I.......(see) my dentist later

2.A:I......(think) of visiting Jim this afternoon.

B:Don't brother.I..........(think) he's on a business trip.

3.A:Why........(Greg/be) so rude today?

B:I have no idea.He.........(be) usually very polite.

4.A:Why..........(you/taste) the sauce?Does it need more pepper?

B:No.It .........(taste) great the way it is.

5.A:Why........(you/smell) the milk?

B:Because it..........(smell) of.We should throw it alway.

6.A:I see you ........(have) a new mobile phone

B:Yes,but I........(have) trouble understanding how it work

VII. Complete the sentences. Use Present perfect or Past simple

a.

A:I(1)...........(see/not) you for a long time. Where(2)..............(you/be)?

B:I(3).............(come/just) back from Canada.

A:Oh really?What(4)....................(you/do) in Canada?

B:I(5).....................(take) a nature tour.

A:Wow!(6)............(you/see) many wild animals there?

B:pf course.I(7)................(watch) bears. wolves and whales in the wild.That(8)...........(be) so interesting.(9)..................(you/spend/ever) a holiday in Canada?

A:Yes,I(10).........................(travel) around Canada twice so far.

B:When (11)..................(you/go) there?

A:The first time I(12)..........................(go) there(13)....................(be) in 1997 and the second time in 2004

B:(14)....................(you/enjoy) it?

A:I absolutely(15)....................(love) it,especially the west coast.

chuyển câu sau sang bị động:

are you roasting chestnuts now?

III. Sắp xếp lại câu bị xáo trộn

a) always/class/time/we/to/come/on.

→.......................................................................................

b) hours/week/often/does/how/he/many/a/work.

→.......................................................................................

c) not/American/uniforms/do/usually/school/wear/students.

→.......................................................................................

d) 10:00/at/Wednesday/Science/Nam/class/on/has.

→.......................................................................................

e) interesting/I/because/Math/it/like/is.

→.......................................................................................

i) like/what/does/subject/best/Tom.

→.......................................................................................

g) you/work/to/want/we/with.

→.......................................................................................

h) Know/you/do/likes/he/how/meat?

→.......................................................................................

l) There/excuse/a/!/post/is/me/near/office/here?

→.......................................................................................

m) That/you/the/ , / want/is/post/letter/to/Mai?

→.......................................................................................

n) Is/interestes/Mai/experiments/doing/in

→.......................................................................................

o) him/tell/I'll/please/call/after/5/again.

→.......................................................................................

k) Huong/be/November 20th/ , / twelve/on/will/Saturday.

Bài 1:Sắp xếp lại câu bị xáo trộn:

1/ not/American/uniforms/do/usually/school/wear/students.

2/ hours/week/often/does/how/he/many/a/work?

3/ 10:00/at/Wednesday/Science/Nam/class/on/has.

4/ interesting/I/because/Math/it/like/is.

5/ like/what/does/subject/best/Tom?

Bài 2:Viết câu tương đương

1/What about going to the movies?

→Why......................................................................................................

2/Where does she live?

→What.....................................................................................................

3/What do you do?

→What.....................................................................................................

4/The dress is very old.

→What............................................................................................!

5/What subject does she like best?

→What is........................................................................................

6/How much is the hat?

→How much does...........................................................................?

7/Lan is taller than Hoa

→Hoa is........................................................................................

8/No one in the group is taller than Trung

⇒Trung.........................................................................................

9/I get to work in half an hour

⇒It takes......................................................................................

10/How is this dictionary?

⇒How much does............................................................................

11/How about eating out tonight in a restaurant?

⇒Why don't we................................................................................

Tìm các số nguyên n để 3n-2⋮n+3