Bài 3: 

a: Xét ΔADC có 

\(\dfrac{AM}{MD}=\dfrac{AP}{PC}\)

Do đó: MP//DC

Xét ΔCAB có 

\(\dfrac{CQ}{QB}=\dfrac{CP}{PA}\)

Do đó: PQ//AB

hay PQ//CD

Xét ΔBCD có 

\(\dfrac{BQ}{QC}=\dfrac{BN}{ND}\)

Do đó: NQ//DC

Ta có: PQ//CD

NQ//DC

mà PQ và NQ có điểm chung là Q

nên Q,P,N thẳng hàng(1)

Ta có: PQ//CD

PM//CD

mà PQ và PM có điểm chung là P

nên M,P,Q thẳng hàng(2)

Từ (1) và (2) suy ra M,N,P,Q thẳng hàng

V

2 The alpine scenery (land) is very dramatic. (Cần danh từ chỉ phong cảnh)

3 Women who are slimming can never enjoy a meal without being afraid of disorganizing (organize) their diet.

4 She always listens attentively (attention) to what she is told.

5 He was informed (information) of the consequences in advance. (Cấu trúc bị động: be + V3/ed)

6 The professor explained his ideas with great clarity (clear). (Sau "great" cần một danh từ)

7 The cost of the carriage (carry) must be repaired by the buyer.

1: Khi x=3-2 căn 2 thì \(A=\dfrac{\sqrt{2}-1+2}{\sqrt{2}-1}=\dfrac{\sqrt{2}+1}{\sqrt{2}-1}=3+2\sqrt{2}\)

2: \(B=\dfrac{x+\sqrt{x}+2+\sqrt{x}-2}{x-4}=\dfrac{x+2\sqrt{x}}{x-4}=\dfrac{\sqrt{x}}{\sqrt{x}-2}\)

3: \(P=A:B=\dfrac{\sqrt{x}+2}{\sqrt{x}}:\dfrac{\sqrt{x}}{\sqrt{x}-2}=\dfrac{x-4}{x}\)

\(x\cdot P< =10\sqrt{x}-29-\sqrt{x-25}\)

=>\(x-4< =10\sqrt{x}-29-\sqrt{x-25}\)

\(\Leftrightarrow x-4-10\sqrt{x}+29< =-\sqrt{x-25}\)

=>\(x-10\sqrt{x}+25< =-\sqrt{x-25}\)

=>(căn x-5)^2<=-căn x-25

=>x-25=0

=>x=25

e cảm ơn ạ

1 traditional

2 Traditionally

3 enjoyable

4 villagers

5 enjoyably

6 entertaining

7 entertainment

8 peace

9 peaceful

10 nature

11 naturally

12 noisily

13 Noise

14 peacefully

15 natural

16 quietly

17 refreshment

18 entertainments

19 entertainment

20 peaceful

Em cảm ơn nhìu ạ 😍💞

1. We decorate the house before Tet

2. In the New Year's Eve, they watch fireworks display

3. What do you do at Christmast

4. Children get a lot of present on Children's Day

5. Teachers's Day is on the twentieth of November

1. decorate / the / we / house / Tet / before
   We decorate the house before Tet.
2. in / the / Eve / they / New Year’s / watch / displays / firework
   They watch firework displays in the New Year's Eve.
3. you / Christmas / do / what / at / do
   What do you do at Christmas?

4. a / presents / of / get / Children’s / lot / on / Children / Day
   Children get a lot of presents on Children's Day.
5. twentieth / Teachers’ / is / the / Day / on / of / November
   Teacher's Day is on the twentieth of November.

Phần cứng và phần mềm.

tk

CPU (Centtkral Processing Unit) ...

RAM (Random Access Memory) ...

Ổ cứng (HDD hoặc SSD) ...

Bộ nguồn (Power Supply hay PSU) ...

Card đồ họa (Graphics Card) ...

Mainboard (Bo mạch chủ)

no no thi kko chỉ đc 

Mik thi r nhá

e: \(\left(-4156+2021\right)-\left(119+2021-4156\right)\)

\(=-4156+2021-119-2021+4156\)

\(=\left(-4156+4156\right)+\left(2021-2021\right)-119\)

=0+0-119

=-119

g: \(315\cdot75-\left(15\cdot100-315\cdot25\right)\)

\(=315\cdot75-15\cdot100+315\cdot25\)

\(=315\left(75+25\right)-15\cdot100\)

\(=315\cdot100-15\cdot100=300\cdot100=30000\)

h: \(\left(-489\right)\cdot125-\left(125\cdot11-500\cdot25\right)\)

\(=-489\cdot125-125\cdot11+500\cdot25\)

\(=125\left(-489-11\right)+500\cdot25\)

\(=125\cdot\left(-500\right)+500\cdot25\)

\(=500\left(-125+25\right)\)

\(=500\cdot\left(-100\right)=-50000\)

Bài 2:

a: \(-415-3\left(2x-1\right)^2=-490\)

=>\(3\left(2x-1\right)^2+415=490\)

=>\(3\left(2x-1\right)^2=75\)

=>\(\left(2x-1\right)^2=25\)

=>\(\left[{}\begin{matrix}2x-1=5\\2x-1=-5\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=6\\2x=-4\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}x=3\\x=-2\end{matrix}\right.\)