Bài 5: 

\(\widehat{BKC}=180^0-\left(\widehat{KBC}+\widehat{KCB}\right)\)

\(=180^0-\dfrac{180^0-80^0}{2}\)

\(=180^0-50^0=130^0\)

CH4+Cl2-as->CH3Cl+HCl

CaC2+2H2O->Ca(OH)2+C2H2

C2H2+5\2O2-to>2CO2+H2O

C2H2+2H2-xt->C2H6

bài 5

C2H5OH+3O2-to>2CO2+3H2O

0,5------------1,5--------1 mol

n C2H5OH=0,5 mol

=>VCo2=1,5.22,4=33,6l

b)Vkk=1,5.22,4.5=168l

b d d c a

1.B
2.D
3.D
4.A
5.A

1. Where is the book?

2. What did they look after a long walk?

3. What make people different from all other animals?

4. Who is Jane waiting for?

5. Why did you have to cancel your picnic?

6. How long does it take to ride to VT by motorbike?

7. Who is Mimi talking to Fred about?

8. How often do you go to E club?

9. Why do you often go for a walk at night?

10. Where are you going for holiday this summer?

11. Who is your father going to take to the zoo next Sunday?

12. What do you study English for?

Bài 4:

Vì  \(\left\{{}\begin{matrix}AB=AC\\BM=MC\\AM.chung\end{matrix}\right.\) nên \(\Delta AMB=\Delta AMC\left(c.c.c\right)\)

Do đó \(\left\{{}\begin{matrix}\widehat{AMB}=\widehat{AMC}\\\widehat{MAB}=\widehat{MAC}\end{matrix}\right.\)

Mà \(\widehat{AMB}+\widehat{AMC}=180^0\) nên \(\widehat{AMB}=\widehat{AMC}=90^0\) hay AM⊥BC

\(\widehat{MAB}=\widehat{MAC}\) (cm trên) nên AM là pg góc BAC

\(f(x)=ax^2+bx+6\)

Để \(f(x)\) là đa thức bậc \(1\) thì \(ax^2=0\)

\(→a=0\)

Thay \(x=1\) vào \(f(x)=ax^2+bx+6\)

\(f(1)=b.1+6=b+6\)

Mà \(f(1)=3\)

\(\Rightarrow b+6=3\Rightarrow b=3−6\Rightarrow b=−3\)

Vậy \(a=0;b=−3\)

1 D

2 B

3 A

4 B

5 B

6 A

7 D

8 A

9 A

10 B

11 A

12 C

13 B

14 C

15 B

16 A

1 D

2 B

3 A

4 A

5 C

6 B

7 B

8 B

9 B

10 B

11 C

12 C

13 C

14 C

15 D

D B A A C B B B B B C C C C D