\(18=\sqrt{18^2}=\sqrt{324}\)
\(\sqrt{15}\cdot\sqrt{17}=\sqrt{255}\)
vì \(324>255\Rightarrow\sqrt{324}>\sqrt{255}\Rightarrow18>\sqrt{15}\cdot\sqrt{17}\)

các bạn ơi cho mình xin cách làm nhé

thanks bạn đã trả lời !^^ mình đã k rồi đó ^^!!!!!
 

Dấu hiệu chia hết cho 2: các số có chữ số tận cùng là 0, 2, 4, 6, 8 (nói chung là số chẵn) thì chia hết cho 2

Vd: 24, 36, 78,....

Dấu hiệu chia hết cho 3: các số có tổng các chữ số của số đó chia hết cho 3 thì số đó chia hết cho 3 

Vd : 81, 102, 87, ...

=20+10=30

A={0;1;2;3;4;5;6;7;8;9}

Give the correct form of the verbs in brackets.

1)Almost everybody(leave)...................by the time we(arrive)..................

2)He(wonder)..................whether he(leave)..................his wallet at home .

3)The secretary(not leave)....................until she(finish).................her work.

4)The couple scarcely (enter)..................the house when they(begin)..................to argue.

5)The teacher(ask)...................the boy why he(not do)................his homework.

6)She already(post)...................the letter when she(realize)...................she(send)....................it to the wrong address

7)Hardly the car(go)....................a mile when it(have).....................a flat tyre.

8)The weather(be)....................far worse than we (expect)..................

9)They(be married)....................for five years when they finally(have)....................a child.

10)No sooner they (sell)....................their car than they(regret)....................having done so.

11)When she(finish)...................her work she(go)....................to the cinema.

12)He(not eat).....................until his parents(come)...................home.

13)She(tell)..................me she never(meet)....................him.

14)He(do)..................her homework before he(go)...................out.

15)The lights(go)....................out the moment he(get)..................into the cinema.

16)Hardly the holiday(begin)....................when they(leave)....................the town.

17)They(be)....................out for an hour when it(start)....................to rain.

18)They(leave)....................the shop as soon as they(buy)....................everything they(need)................

19)The house(burn)..................to the ground by the time the firemen(arrive)........................

20)As he(do).......................a lot of work that day he(be)......................very tired.

mik sắp kiểm tra làm nhanh giùm mik

choose the best answer:

1)..................means a person warking in the street and not travelling in a vehicle

A.Pedestrian B.Elevated walkway C.Flyover

2)..................is one of the separate sections which a coach/car or a train is divided into.

A.Thatched house B.Tunnel C.Compartment

3).................means a bridge that carries one road over another one.

A.Flyover B.Underpass C.Tunnel

4).....................is defined as a passage built underground,for example to allow a road or railroad to go through a hill or under a river.

A.Elevated walkway B.Tunnel C.Thatched house

5).....................means a house that has a roof that is thatched with straw,need,or similar material.

A.Compartment B.Tunnel C.Thatched house

6)...................is a road or path that goes under another road or railroad track.

A.Underpass B.Pedestrian C.Compartment

tốt lắm còn ai ko