Kẻ AH⊥BC

ta có: \(VP=AB^2+BC^2-2.AB.BC.cosB=AB^2+BC^2-2.AB.BC.\dfrac{BH}{AB}=AB^2+BC^2-2.BH.BC=AB^2-BH^2+BC^2-2.BH.BC+BH^2=AH^2+\left(BC-BH\right)^2=AH^2+CH^2=AC^2=VT\)

Tham khảo nhe =)) 

Dùng những từ gợi ý sau để viết các câu hoàn chỉnh.

1. I/ receive/ letter/ uncle/ last week

==>I received a letter from my uncle last week.

2. yesterday/ doctor/ tell/ Hoa/ not/ forget/ brush/ teeth/ every day.

==>Yesterday,the doctor told Hoa not to forget to brush her teeth everyday.

3. I/ tell/ classmates/ my trip/ Tri Nguyen Aquarium/ Nha Trang.

==>I told my classmates about my trip in Tri Nguyen Aquarium in Nha Trang.

4.Yesterday/ I/ toothache/ so/ I/ go/see/ dentist

==>Yesterday I had a tooache so I went to see the dentist.

5. Dentist/ check/his teeth/ and/ tell/ him/not/ worry.

==>Dentist checked his teeth and told him no to worry.

6. She/ always/ get up/ early/ do morning exercises.

==>She always gets up early to do morning exercises.

7. Yesterday/ Minh/ feel/ less/ scared/ after/ Dr. Lai/ check/ his teeth.

==>Yesterday Minh felt less scared after Dr.lai checked his teeth.

8. Tam/ look/ tired/ because/ she/ stay/ late/ last night.

==>Tom looked tired because she stayed late last night.

1. I/ receive/ letter/ uncle/ last week

=>I received a letter from my uncle last week.

2. yesterday/ doctor/ tell/ Hoa/ not/ forget/ brush/ teeth/ every day.

=>Yesterday,the doctor told Hoa not to forget to brush her teeth everyday.

3. I/ tell/ classmates/ my trip/ Tri Nguyen Aquarium/ Nha Trang.

=>I told my classmates about my trip in Tri Nguyen Aquarium in Nha Trang.

4.Yesterday/ I/ toothache/ so/ I/ go/see/ dentist

=>Yesterday I had a tooache so I went to see the dentist.

5. Dentist/ check/his teeth/ and/ tell/ him/not/ worry.

=>Dentist checked his teeth and told him no to worry.

6. She/ always/ get up/ early/ do morning exercises.

=>She always gets up early to do morning exercises.

7. Yesterday/ Minh/ feel/ less/ scared/ after/ Dr. Lai/ check/ his teeth.

=>Yesterday Minh felt less scared after Dr.lai checked his teeth.

8. Tam/ look/ tired/ because/ she/ stay/ late/ last night.

=>Tom looked tired because she stayed late last night.

\(2\overrightarrow{MA}+\overrightarrow{BM}+\overrightarrow{MC}=k.\overrightarrow{BC}\Leftrightarrow2\overrightarrow{MA}+\overrightarrow{BC}=k.\overrightarrow{BC}\)

\(\Leftrightarrow2\overrightarrow{MA}=\left(k-1\right)\overrightarrow{BC}\)

\(\Leftrightarrow\overrightarrow{MA}=\left(\dfrac{k-1}{2}\right)\overrightarrow{BC}\)

\(\Leftrightarrow\overrightarrow{MA}\) cùng phương \(\overrightarrow{BC}\)

 
\(\Rightarrow\) Tập hợp M là đường thẳng qua A và song song BC

C nha

Kiểu này là thi òi:)

Mik thi như này nhìu nên bít:>

a: 

Input: a=20

Output: a*a

She does not go to school at 8 o'clock
He does not have dinner at 9 o'clock
She does not go to bed at 7 o'clock
He does not go home at 4 o'clock
He does not go to bed at 9 o'clock

Hình một đâu vậy em :v?

Nghệ thuật:

 - Xây dựng luận điểm ngắn gọn, xúc tích; lập luận chặt chẽ; dẫn chứng toàn diện, chọn lọc tiêu biểu theo các phương diện: lứa tuổi, tầng lớp, vùng miền,...

 - Sử dụng từ ngữ gợi hình ảnh: làn sóng, lướt qua,... và câu văn nghị luận hiệu quả

 - Sử dụng phép so sánh, liệt kê nêu tên các anh hùng dân tộc trong lịch sử chống giặc ngoại xâm, nêu các biểu hiện của lòng yêu nước

10+10=20

TL +20 nha

t đang cày sp nên xin tích

học tốt

thêm 1 dòng cho nó dài:)

10 + 10 = 20