1D 2C 3D 4B 6C 7A 8B 9D 10C 11C 12C

1.Her voice is better than ........

 A.my               B.my voice               C.mine              D.B và C

2.Mia's favourite type of music is Jazz,........is blue

A.me                   B.myself                      C.mine                 D.myself

3.She sings better than ..........

A.my                   B.mine                         C.myself               D.me

4.Although .......... leg was broken,he managed to go to work

A.her                   B.his                            C.him                   D.herself

5.I ........ want to be in the top 10

A.me                   B.myself                       C.mine                 D.my

6.He is thinking about what ......... can do for his family

A.him                  B.his                              C.he                    D.himself

C => in order

B => more fluently

C => in order

B => more fluently

1. was

2. is doing

3. rises

4. is having

5. collected

6. are - picking

7. Did - volunteer

8. watches

9. am not studying

10. threw 

1. was

2. is doing

3. rises

4. is having

5. collected

6. are you picking

7. Did Jenny volunteer

8. watches

9. am not studying

10. threw

TK:

1. books

-> collecting books: thu thập, sưu tầm sách

2. a (a/an + N số ít)

3. of (a book of any kinds: một cuốn sách của bất kỳ loại nào)

4. healthy (stay healthy: giữ gìn sức khỏe)

5. happy: hạnh phúc

1 books

2 the

3 of

4 healthy

5 happy

\(\left(7x+2\right)^{-1}=3^{-2}\)

=>\(\dfrac{1}{7x+2}=\dfrac{1}{3^2}=\dfrac{1}{9}\)

=>7x+2=9

=>7x=7

=>x=1

1: (2x-1)*x>0

TH1: \(\left\{{}\begin{matrix}2x-1>0\\x>0\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x>\dfrac{1}{2}\\x>0\end{matrix}\right.\Leftrightarrow x>\dfrac{1}{2}\)

TH2: \(\left\{{}\begin{matrix}2x-1< 0\\x< 0\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x< \dfrac{1}{2}\\x< 0\end{matrix}\right.\)

=>x<0

2: 
ĐKXĐ: x<>1

\(\dfrac{x+3}{x-1}< 0\)

TH1: \(\left\{{}\begin{matrix}x+3>0\\x-1< 0\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x>-3\\x< 1\end{matrix}\right.\)

=>-3<x<1

TH2: \(\left\{{}\begin{matrix}x+3< 0\\x-1>0\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x< -3\\x>1\end{matrix}\right.\)

=>Loại

c: 

ĐKXĐ: x<>0

\(\dfrac{x^2-2}{5x}< 0\)

TH1: \(\left\{{}\begin{matrix}x^2-2< 0\\5x>0\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x^2< 2\\x>0\end{matrix}\right.\Leftrightarrow0< x< \sqrt{2}\)

TH2: \(\left\{{}\begin{matrix}x^2-2>0\\5x< 0\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x^2>2\\x< 0\end{matrix}\right.\Leftrightarrow-\sqrt{2}< x< 0\)

d: (x-3)(x+7)>0

TH1: \(\left\{{}\begin{matrix}x-3>0\\x+7>0\end{matrix}\right.\)

=>\(\left\{{}\begin{matrix}x>3\\x>-7\end{matrix}\right.\Leftrightarrow x>3\)

TH2: \(\left\{{}\begin{matrix}x-3< 0\\x+7< 0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x< 3\\x< -7\end{matrix}\right.\)

=>x<-7

Bài 1

1 He gets up at 7 o'clock everyday

2 Ann goes to school at 8 o'clock

3 I call my friends every morning

4 Liz sends messages to her friends

5 They like to play football very much

6 Tim goes to the zoo every week

7 We work hard at our English

Bài 2

1 Jim often watches football matches on Sundays

2 I usually ride my bike in the evening

3 Janes always write invitations to her friends

4 Boys usually spend the whole afternoon in the gym

5 They never take part in football competition

6 Bob sometimes buys books in the nearest bookshop

7 We usually go to the cinema everyday

Sửa đề:

 \(3^{2n+3}-3^{2n+2}=2\cdot3^{10}\\ \Rightarrow3^{2n+2}\cdot3-3^{2n+2}=2\cdot3^{10}\\ \Rightarrow3^{2n+2}\cdot\left(3-1\right)=2\cdot3^{10}\\ \Rightarrow2\cdot3^{2n+2}=2\cdot3^{10}\\ \Rightarrow3^{2n+2}=3^{10}\\ \Rightarrow2n+2=10\\ \Rightarrow2n=8\\ \Rightarrow n=4\)

Vậy...