B= \(\dfrac{a^2+b^2}{ab}+\dfrac{ab}{a^2+b^2}\) với a, b > 0

TÌM GIÁ TRỊ NHỎ NHẤT

dạng 3 : Tìm giá trị lớn nhất của biểu thức 

A= \(\dfrac{3x^2+3x+4}{x^2+x+1}\)

Find the once choice that best completes the passage below :

Nowadays, people are destroying rain forests of the earth seriously. It is  (15)……………….. that every year 100,000 (16)……………….. kilometers of rain forests are destroyed for (17)……………….. of wood paper and fuel as well as for the residence and (18)………………..  land. Rain forests are very  important for the world’s climate. They receive the rainfall on the earth and produce a large amount of the world’s oxygen. Destroying rain forests,(19)………………..  , is destroying our environment. Saving rain forests is a(n) (20)………………..  problem. Nations need cooperation to save rain forests, if not, it will be late.

5.      A. exhausted               B. pleasure              C. interesting           D. estimated

6.      A. square                               B. cross                   C. round          D. heart

7.      A. bring                      B. supply                 C.  support              D. suggest

8.      A. planting                  B. field                              C. farming       D. rice

9.      A. moreover                B. however             C. so                       D. therefore

10.   A. national                  B. international        C. world wide            D. world

5.    The boys looks very proud …………his success at school.

A. of                     B. at                       C. about                            D. on    

6.    Is Dalat rather crowded?- No, there are …………people than in HCM.

A. few                  B. fewer                  C. more                             D. less

7.     In spite of ………late, he arrived in time.

A. he started                    B. his being started  C. he was started             D. starting    

8.     It’s time the children ………here now.

A. are                   B. are being            C. were                             D. to be

9.     I won’t go …………you  explain everything to me.

A. unless               B. although             C. because                         D. if     

10.  How many languages are there ……………the world?

A. through             B. over                              C. for                              D. in  

11.  Your son is not only intelligent ……………… handsome.

A. but also            B. and                     C. but                                D. with 

12.  The washing machine was very expensive, ………we couldn’t afford to buy it.

A. though              B. because              C. therefore                       D. so    

13.  This is …………novel I’ve read.

A. bad                   B. good                   C. better                            D. the worst

14.  They don’t understand the matter ; ……………they didn’t ask for help.

A. moreover                    B. therefore             C. however                     D. but

I.           Rewrite the following sentences using IF.

1.     I didn’t have enough money. I didn’t take a taxi.

……………………………………………………………………………………………….                                         

2.     I wasn’t interested in the film. I didn’t go to the cinema.

……………………………………………………………………………………………….                             

3.     We took the wrong turning. We arrived late.

………………………………………………………………………………………………                                                     

4.     She doesn’t take exercise regularly, so she is fat.

………………………………………………………………………………………………                             

5.     Follow the instruction or you will ruin everything.

……………………………………………………………………………………………….                             

6.     Try harder or you will fail in the next exam.  

………………………………………………………………………………………………                             

7.     We didn’t have your address so we didn’t send you a Christmas card.

………………………………………………………………………………………………

8.     We can’t have lunch in the garden because it is raining.

……………………………………………………………………………………………..

9.     I forget my credit card so I couldn’t pay for my groceries.

……………………………………………………………………………………………..

10.  Alex didn’t pay the electric bill. The electric company cut off his power.

…………………………………………………………………………………………….

11.  The weather was bad. The outdoor concert was cancelled.

…………………………………………………………………………………………….

12.  My brother was sick yesterday so he didn’t go to class.

…………………………………………………………………………………………….

1.     I didn’t have enough money. I didn’t take a taxi.

……………………………………………………………………………………………….                                         

2.     I wasn’t interested in the film. I didn’t go to the cinema.

……………………………………………………………………………………………….                             

3.     We took the wrong turning. We arrived late.

………………………………………………………………………………………………                                                     

4.     She doesn’t take exercise regularly, so she is fat.

………………………………………………………………………………………………                             

5.     Follow the instruction or you will ruin everything.

……………………………………………………………………………………………….                             

6.     Try harder or you will fail in the next exam.  

………………………………………………………………………………………………                             

7.     We didn’t have your address so we didn’t send you a Christmas card.

………………………………………………………………………………………………

8.     We can’t have lunch in the garden because it is raining.

……………………………………………………………………………………………..

9.     I forget my credit card so I couldn’t pay for my groceries.

……………………………………………………………………………………………..

10.  Alex didn’t pay the electric bill. The electric company cut off his power.

…………………………………………………………………………………………….

11.  The weather was bad. The outdoor concert was cancelled.

…………………………………………………………………………………………….

12.  My brother was sick yesterday so he didn’t go to class.

…………………………………………………………………………………………….

1.     Adam met his future wife, Alice, on a flight to Tokyo. If he (not take) …don’t took… that flight, he (not meet) …would’t meet……………… Alice.

2.     If you (throw) …throw…………………a stone into the lake, it (sink)……sink………………………

3.     I (know) …know……………… that Jane was in hospital, I (visit) …vistis……………… her.

4.     If Alexander Fleming (not discover) …don’t discover the medical usefulness of a certain kind of mold, scientists (not develop) …don’t……………… penicillin.

5.     If I (have)…………………….her phone number, I (give) ……………………….you. But in fact, I don’t have it.

6.     If Harry (not fall) ………………… asleep yesterday, he (not crash) ………………… into the tree

7.     If you (not be) ………………… rude to Jerry at the party last night, she (not get) ………………… so angry.

8.     Please study for your exam next week. If you (not, work) …………………………..hard, you (fail) …………………..the exam.

9.     If I (have).......................enough money, I (backpack)............................around Europe. But, unfortunately, I am broke.

10.  She (not/ be)........................................here earlier if she (not/ miss)........................................the train last night.

11.  If we (not, leave) …………………………….now, we (be) ………………………late for our train. Hurry up!

12.  Thank you for helping me study. If you (not/ tutor).....................................me, I (fail)....................................the test.

13.  My business trip to Paris was only two days. If the trip (be) ....................................longer, I (visit) ....................................

14.  My uncle lives so far away from us. If he (live) ………………………..near us, I (visit) ……………………….him more often.

15.  I don’t know her address. If I (know) ....................................her address, I (come) ....................................to see her.1.     Adam met his future wife, Alice, on a flight to Tokyo. If he (not take) …don’t took… that flight, he (not meet) …would’t meet……………… Alice.

2.     If you (throw) …throw…………………a stone into the lake, it (sink)……sink………………………

3.     I (know) …know……………… that Jane was in hospital, I (visit) …vistis……………… her.

4.     If Alexander Fleming (not discover) …don’t discover the medical usefulness of a certain kind of mold, scientists (not develop) …don’t……………… penicillin.

5.     If I (have)…………………….her phone number, I (give) ……………………….you. But in fact, I don’t have it.

6.     If Harry (not fall) ………………… asleep yesterday, he (not crash) ………………… into the tree

7.     If you (not be) ………………… rude to Jerry at the party last night, she (not get) ………………… so angry.

8.     Please study for your exam next week. If you (not, work) …………………………..hard, you (fail) …………………..the exam.

9.     If I (have).......................enough money, I (backpack)............................around Europe. But, unfortunately, I am broke.

10.  She (not/ be)........................................here earlier if she (not/ miss)........................................the train last night.

11.  If we (not, leave) …………………………….now, we (be) ………………………late for our train. Hurry up!

12.  Thank you for helping me study. If you (not/ tutor).....................................me, I (fail)....................................the test.

13.  My business trip to Paris was only two days. If the trip (be) ....................................longer, I (visit) ....................................

14.  My uncle lives so far away from us. If he (live) ………………………..near us, I (visit) ……………………….him more often.

15.  I don’t know her address. If I (know) ....................................her address, I (come) ....................................to see her.