(2x+1)+(4x+2)+...+(400x+200)

\(=\left(2x+1\right)+2\left(2x+1\right)+...+200\left(2x+1\right)\)

\(=\left(2x+1\right)\left(1+2+...+200\right)\)

\(=\left(2x+1\right)\cdot\dfrac{200\left(200+1\right)}{2}=20100\left(2x+1\right)\)

Em cần làm gì với biểu thức này vậy?

Để A nguyên thì \(2024⋮x-2\)

=>\(x-2\in\){1;-1;2;-2;4;-4;8;-8;11;-11;22;-22;23;-23;44;-44;46;-46;88;-88;92;-92;184;-184;253;-253;506;-506;1012;-1012;2024;-2024}

=>x\(\in\){3;1;4;0;6;-2;10;-6;13;-9;24;-20;25;-21;46;-42;48;-44;90;-86;94;-90;186;-182;255;-251;508;-504;1014;-1010;2026;-2022}

V. Write suitable questions for the answers given. (0,75 point) 

VI. Read and write T (True) or F (False). (0,75 point)

1. It was rainy on Monday.                                                     _____F______

2. I was at the park on Friday.                                              _____F______

3. There were lots of photos of the rainbow on Saturday.    ______T_____

VII. Fill in the blanks. (1 point)

My name is Martin and I live in a small town. In my town, there is a (1) ____bookshops_______ and a (2) ________bakery______. There is a bus stop but there aren’t any airports. There are lots of houses, but there aren’t any tall buildings. My favourite place is the (3)  _____waterpark_____. It’s near a (4)  ____souvenir shop_______. I love playing with my little brother there.

VIII. Write suitable answers to the questions using given words. (1 point)

1. Why do you like horses?

⭢ _______Because they run quickly________________________________________________

2. What are they doing?

⭢ ___They are putting up a tent____________________________________________________

3. What does it say?

⭢ __It say turns right_____________________________________________________

4. What was the weather like yesterday?

⭢ _______________It was cloudy________________________________________

Ta thấy :

\(45^{10}=9^{10}.5^{10}=3^{20}.5^{10}=\overline{...1}.\overline{...5}=\overline{.....5}\) (vì số tận cùng là 3 và 5)

\(5^{40}=\overline{.....5}\) (vì số tận cùng là 5)

\(\Rightarrow45^{10}-5^{40}=\overline{.....0}\)

mà \(25^{20}=5^{40}=\overline{.....5}\) (vì số tận cùng là 5)

\(\Rightarrow45^{10}-5^{40}:25^{20}=\overline{.....0}\)

\(\Rightarrow45^{10}-5^{40}⋮25^{20}\) \(\left(dpcm\right)\)

IV. Read and choose A, B or C.

V. Write suitable questions for the answers given.

VI. Read and write T (True) or F (False).

Lizzy was at the zoo with her parents. For lunch, there were some sandwiches for her mum and a hamburger for her dad. There were some giraffes in their photos. Next, they were able to see the monkeys. The monkeys were able to swing from the trees and they were so funny. That was their great day at the zoo.

1. There were some sandwiches and a hamburger for her parents.  ______T____

2. There were some monkeys in the photos.                    _____F_____

3. The monkeys were very funny.                              ____T______

VII. Fill in the blanks. 

Today, I go to a campsite with my family. The weather is (1)  _______sunnyg_____. We get to the campsite by car. When we arrive, we put up a big (2) _____tent_____. My dad builds a (3) ______campfire_______. We cook and sing songs around it, too. My sister brings some cards and we play (4)  _______cards______ together.

VIII. Write suitable answers to the questions using given words. 

1. What does it say?

⭢ _________It says "go straight"____________________________________________________

2. What are these animals?

⭢ ____They are crocodiles_________________________________________________________

3. What was the weather like last weekend?

⭢ ______It was rainy_______________________________________________________

4. What is Lan doing?

⭢ ___________She is telling a story__________________________________________________

Thay x=4 và y=3 vào biểu thức, ta được:

\(\dfrac{2\cdot4+3\cdot3}{4^2-3^2}=\dfrac{8+9}{7}=\dfrac{17}{7}\)

A = \(\dfrac{2x+3y}{x^2-y^2}\)

Thay \(x=4;y=3\) vào A ta có: 

A = \(\dfrac{2.4+3.3}{4^2-3^2}\)

A = \(\dfrac{8+9}{16-9}\)

A = \(\dfrac{17}{7}\)
:

Theo bài ra ta có: \(\left\{{}\begin{matrix}86-11⋮a\\142-27⋮a\end{matrix}\right.\)⇒ \(\left\{{}\begin{matrix}75⋮a\\115⋮a\end{matrix}\right.\) ⇒ a \(\in\) ƯC(75; 115)

 75 =  3.5²; 115 =  5.23 ⇒ ƯCLN(75; 115) = 5

⇒ a \(\in\) Ư(5) = {1; 5}

vì a > 27 nên không có giá trị nào của a thỏa mãn đề bài

GIÚP MÌNH VÓI MÌNH THẤY ĐỀ BÀI CÓ GÌ ĐÓ SAI MONG CÁC BẠN SỦA GÚP VÀ GIẢ ,VẼ HÌNH NỮA NHÉ

MÌNH CẢM ƠN

a) Xét tam giác ABH và tam giác DBH có:

 AB = BD (g.t)

 BH chung

 HA = HD (g.t)

b) Ta có: Góc BHA = Gó BHD =90*

=> HE là trung trực

=> EA = ED

=> Tam giác AED cân

\(\left(x-0,3\right)^2=9\\ =>\left(x-0,3\right)^2=3^2\\TH1:x-0,3=3\\ =>x=3+0,3\\ =>x=3,3\\ TH2:x-0,3=-3\\ =>x=-3+0,3\\ =>x=-2.7\)

a: Xét ΔABE và ΔACE có

AB=AC

\(\widehat{BAE}=\widehat{CAE}\)

AE chung

Do đó: ΔABE=ΔACE

b: ΔABE=ΔACE

=>BE=CE
=>E là trung điểm của BC

=>E nằm trên đường trung trực của BC(1)

Ta có: AB=AC
=>A nằm trên đường trung trực của BC(2)

Từ (1),(2) suy ra AE là đường trung trực của BC