12

22

2

èwere

=12 

=22

= 2

Giống Shino r.

Bị k sai nhưng ko trừ điểm thế mới hay chứ

Học tốt

Trả lời:

Cx có thể là do câu trả lời quá ngắn hoặc dài

Hok tốt nhé

\(A=1.2+2.3+3.4+...+9.10\)

\(3A=1.2.3+2.3.\left(4-1\right)+3.4.\left(5-2\right)+...+9.10.\left(11-8\right)\)

\(3A=1.2.3+2.3.4-1.2.3+3.4.5-2.3.4+...+9.10.11-8.9.10\)

\(3A=9.10.11\)

\(A=\frac{9.10.11}{3}=\frac{990}{3}=330\)

Tớ làm để giúp cậu chứ k có y muốn xin

\(A=1.2+2.3+3.4+.....+9.10\)

\(\frac{1}{A}=\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+.....+\frac{1}{9.10}\)

\(\frac{1}{A}=\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+......+\frac{1}{9}-\frac{1}{10}\)

\(\frac{1}{A}=\frac{1}{1}-\frac{1}{10}=\frac{9}{10}\)

\(A=1:\frac{9}{10}=\frac{1.10}{9}=\frac{10}{9}\)

ko đăng câu hỏi linh tinh

kb nha,k mk đi

haizz,nếu kb thì pk nc nx chứ

^^,đg buồn

ai lm mk vui đc hông nak

Đề 1 : Talk about your bestfriend

Hello everybody,my name is Vy.If you want me to tell you about one of my friends,I will think about my best friend firstly.

Her name is Duyen.If you ask : "How does she look ".I will answer : She is tall but slim,she has an oval face with straight nose,big eye, warm slime, and long black hair.I think a Vietnamese girl her is very beautiful.And what about her personality ? She is friendly,careful,kind,.....all good personality that one can have.Not only that, she is a very kind person. Always open your heart to everyone, share, encourage  when you are sad, encourage you to do something you want or even happier than you when you get good things.Duyen want to be a teacher, her mother so she studies very hard and always gets good marks but she never arrogant.Duyen is also a funny girl,she always makes me laugh so much when we meet each other.We always play,study and many many activities together.

Maybe later we will not learn or even meet again but I still want to keep the memories of this beautiful friendship in the heart, forever ...

Finally,I want to say to every body : "“Best friends are the people in your life that make you laugh louder, smile brighter and live better”

---------------------------------------------------------Let the sweet friendship refresh your soul---------------------------------------------------------------- 

đề 1:I have many friends, but i want to tell you about my best friend. Her name is....She is tall and cute. She has dark hair and a round face. We first met each other when we entered primary school. She was my classmate and her seat next to me. We both cooking and reading magazines....We also studying maths and english. But she is a bit better at maths than me. Therefore, she often helps me do maths homework. I really her and I hope to be her best friend forever.

đề 2:............ is the name of my school. It is not very large but it is very beautiful. There are a lot of grean trees along the schoolyard. It has 3 floors. The classroom is full of desks and chair, there is also a blackboard and 8 fans. The teachers are thoughtful and friendly. They always take care of us, so I love them. I have many friènd there. I love my school so much 

Cs j sai thì tc cho mik nhoa <3

1+1=2

2+2=4

23+32=55

1 + 1 = 2

2 + 2 = 4

23 + 32 = 55

army

mình nè

đề khó ko nguyên?

Có ạ , mình có thể kẻ thêm nếu kết quả vẫn đúng nhé 

Mình đã làm và thầy mình đã chỉ

đc bn ạ nhưng bn phải chỉ ra trong lời giả của mik để người khác còn bt nhé

a ) Vì a//b nên : \(\widehat{BAD}+\widehat{ABC}=180^o\)( 2 góc so le trong )

mà \(\widehat{BAD}=90^o\)( GT )

\(\Rightarrow\)\(90^o+\widehat{ABC}=180^o\)

\(\Rightarrow\)\(\widehat{ABC}=180^o-90^o=90^o\)

Vậy \(\widehat{ABC}=90^o\)

b ) Vì a//b nên : \(\widehat{ADC}+\widehat{BCD}=180^o\)( 2 góc trong cùng phía )

mà \(\widehat{BCD}=120^o\)( GT )

\(\Rightarrow\)\(\widehat{ADC}+120^o=180^o\)

\(\Rightarrow\)\(\widehat{ADC}=180^o-120^o=60^o\)

Vậy \(\widehat{ADC}=60^o\)