Câu 2: 

a: \(\sqrt{9x-9}+1=7\)

\(\Leftrightarrow3\sqrt{x-1}=6\)

\(\Leftrightarrow x-1=4\)

hay x=5

b: \(\sqrt{9x+27}-\dfrac{1}{4}\sqrt{16x+48}+\sqrt{x+3}=9\)

\(\Leftrightarrow\sqrt{x+3}=3\)

hay x=6

Câu 3 : 

Trích mẫu thử : 

Cho quỳ tím vào từng mẫu thử : 

+ Hóa đỏ : HCl , H₂SO₄ (Nhóm 1)

+ Hóa xanh : NaOH , Ba(OH)₂ (Nhóm 2)

+ Không đổi màu : NaNO₃

 Cho nhóm 1 tác dụng với nhóm 2 : 

+ Nếu thấy xuất hiện kết tủa trắng trong nước thì chất trong nhóm 1 là H₂SO₄ còn lại HCl , chất trong nhóm 2 là Ba(OH)₂ còn lại NaOH

Pt : \(Ba\left(OH\right)_2+H_2SO_4\rightarrow BaSO_4+2H_2O\) 

 Chúc bạn học tốt

1.needn't

2.impressed

3.the

4.send

5.the

6.who

ko biết đúng ko nữa 

Part 1

1 needn't

2 impressed

3 with

4 send

5 the

6 who

Part 2

1f 2d 3c 4b 5a 6g

Part 3

1 was cooking

2 surfing

3 went

4 was going to visit

5 try

6 widened

7 cultural

8 conveniently

Part 4

1 serious -> seriously

2 well-preserved -> be well-preserved

Part 5

1 my english were good

2 going to the english-

3 area has been spoiled 

4 which I read 

Part 6 

1 without

2 be damaged

3 healthy

4 destruction

Part 7

2F 3F 4F

Câu 1: 

uses crt;

var t:real;

i:integer;

begin

clrscr;

t:=0;

for i:=1 to 100 do 

  t:=t+(sqr(i) mod (2*i));

writeln('So tien sau cung la: ',t:0:0);

readln;

end.

Câu 2: 

const fi='dxau.inp'

fo='dxau.out'

var f1,f2:text;

st:string;

x:char;

dem,i,d:integer;

a:array[1..255]of integer;

begin

assign(f1,fi); reset(f1);

assign(f2,fo); rewrite(f2);

readln(f1,st);

readln(f1,x);

d:=length(st);

dem:=0;

for i:=1 to d do 

  if st[i]=x then 

begin

inc(dem);

a[dem]:=i;

end;

if dem=0 then writeln(f2,'Khong co')

else begin

writeln(f2,dem);

for i:=1 to dem do 

  write(f2,a[i]:4);

end;

close(f1);

close(f2);

end.

Part 1

1 into

2 which

3 happily

4 aspect

5 if

6 compulsory

Part 2

1c 2f 3b 4g 5a 6e

Part 3

1 opened

2 to be finished

3 repairing

4 driving

5 harmful

6 modernize

7 environmentalists

8 effectively

Part 4

1 disappointing -> disappointed

2 come -> came

Part 5

1 succeed although he tried 

2 my father could speak

3 seen such an interesting 

4 being made to protect

Part 6

1 forest

2 climate

3 in

4 fortunatelt

Part 7

1T 2F 3F 4F

Part 1

1 On

2 did

3 would

4 therefore

5 who

6 of

Part 2

1 G

2 A

3 F

4 D

5 B

6 C

Part 3

1 are watered

2 will become

3 has read

4 revising

5 communicate

6 announcement

7 interactive

8 conservationist

Part 4 

1 to travel => travelling

2 that => bỏ

Part 5

1 spoke English as

2 is being used by 

3 he was leaving

4 you can find are 

Part 6

1 walking

2 good

3 experienced

4 burden

f: =-1/8-7/6+3/4-1

=-3/24-28/24+18/24-1

=-31/24+18/24-1

=-13/24-1=-37/24

g: \(=6\cdot\dfrac{-8}{27}-3\cdot\dfrac{4}{9}+\dfrac{4}{3}+4\)

=-48/27+4

=108/27-48/27

=60/27

=20/9

h: \(=\left[6\cdot\dfrac{1}{9}+1+1\right]\cdot\left(-3\right)-1\)

=(2/3+2)*(-3)-1

=-2-6-1

=-3-6=-9

f: -37/24

g: 20/9

h: -9

part 1

1 where

2 which

3 important

4 traditional

5 of

6 even though

part 2

1G 2A 3F 4D 5C 6B

part 3

1 not watching

2 would arrive

3 would pay

4 playing

5 has worked

6 harmed

7 unsuccessful

 8 richly

part 4

1 internation -> international

2 write -> be written

part 5

1 have to be taken

2 spends 2 hours doing

3 unless someone puts

4 which I visited 

part 6

1 natural

2 economically

3 resources

4 before

part 7

1T 2T 3F 4T

Part 1

1 friendliness

2 were

3 after

4 written

5 correspond

6 which

Part2

1 - D

2 - C

3 - A

4 - G

5 - E

6 - F

Part 3

1 should do

2 visiting

3 cut

4 made

5 has learnt

6 modernize

7commercial

8 untreated

Part 4

1 will => would

2 carefully => careful

Part 5

1 I would pay a visit to 

2 planted trees along the

3 going to be sent

4 which I borrowed from

Part 6

1 subtances

2 Industrial

3 frequently

4 that

Part 1

1 friendliness

2 were 

3 after

4 written

5 correspond

6 which

Part 2

1D 2C 3A 4G 5E 6F

Part3

1 have to do

2 visiting

3 cut

4 was making

5 has learnt

6 modernize

7 commercially

8 mistreated

Part 4

1 will -> would

2 carefully -> careful

Part 5

1 to pay a visit

2 planted trees along the

3 going to be sent 

4 that I borrowed from

Part 6

1 substances

2 industrial

3 naturally

4 that 

Part 7

1F 2F 3T 4T