Tìm x,y,z biết:

x:y:z =4:5:6 và x²-2y+z²=18

Cho tam giác ABC vuông tại A , M là trung điểm của BC . Lấy điểm D thuộc cạnh BC . H và I thứ tự là hình chiếu của B và C xuống đường thẳng AD .Đường thẳng AM cắt CI tại N.C/M

a) BH = AI

b)DN vuông với AC

c)BH²+CI² ko đổi D thay đổi trên cạnh BC

Cân bằng phương trình

1.Mg+HCl→MgCl2+H2

2.Al+HCl→AlCl3+H2

3.Fe+H2SO4→Al2(SO4)3+H2

4.Zn+H3PO4→Zn(PO4)2+H2

5.Al+H3PO4→AlPO4+H2

6.Cu+AgNO3→Cu(NO3)2+Ag

7.Al+AgNO3→Al(NO3)3+Ag

8.Al+Fe(NO3)3→Al(NO3)3+Ag

9.Mg+ZnCl2→MgCl2+Zn

10.Zn+FeCl3→ZnCl2+Fe

ToV, V, Ving

1.They are too tired(walk)...........................home

2.She had to ask the boys(stop)...................making noise

3.Her mother invited her(join).........................the activity

4.The man asked him (come)............................there early

5.The teacher told her(stand)..................................up

6.She suggested(eat)..........................out

Rewrite the following sentences

1.Why don't we meet to discuss the problem?

→Let's.....................................................

2.Mr.John would rather watch TV than go to the cinema

→Mr.John prefers...............................................

3.It was impossible to work in that condition.

→Working..........................................

4.John is not old enough to join the club

→John is too........................................

5.Learning English is not easy

→It's..................................................

6.You shouldn't waste your time

→You'd............................................................................

7.Changing money here on a Saturday is difficult

→It's.................................................................

8.It is impossible to park your car during office hours

→Parking.......................................................................

9.It is cheaper to go by rail than by air

→Going.................................................

10.He spent 2 hours repairing the car

→It took...................................................

11.Let't go for a walk

→How............................................................

GIÚP MÌNH VỚI TỐI MÌNH PHẢI NỘP RỒI HUHU

`Verb tenses

1.Alice(leave).......................forWashington as soon as she (finish)....................her exams next week

2.He(finish)..................the work before you(leave)...........here tomorrow

3.We seldom(eat)................before 7 am

Rewrite

1.Linda has cooked for five hours.

→Linda began....................................................

2.It's two years since I met him.

→I haven't...................................................

3.I have never met such a famous person before

→It is............................................................

4.I have studied English for seven years

→I started...............................................

5.I have never stayed in such an expensive hotel before

→This is...............................................................

6.Do you have any experience of driving this kind of car?

→Have you..............................................................

7.Sarah hasn't seen her friends since she left for the United States

→Sarah last..........................................................................

Use the proper form or tense of the verbs in parentheses:

1.Why must people....................electrical socket?(cover)

2.She ought..........................to her parents more frequently.(write)

3. Do you enjoy....................jokes?(tell)

4.........you(meet)..............Robert lately?

5.Nothinh like this(happen)............before

6.We used..................a lot of songs when we were yong(learn)

7.This is the first time he(drive).....................a car.He(never drive)...........a car before

Đề bài:Cân trình phản ứng Hóa Học

1.BaO+N₂O₅→Ba(NO₃)₂

2.K₂O+H₂SO₄→K₂SO₄+H₂O

3.Al₂O₃HCl→AlCl₃+H₂O

4.Fe₂O₃+HNO₃→Fe(NO₃)₃+H₂O

5.Na₂O+H₃PO₄→Na₃PO₄+H₂O

6.Fe₂O₃+H₂SO₄→Fe₂(SO₄)₃+H₂O