345 nhé

345 bn nhé !

a)136.68+16.272=9248+4352=13600

b)=11988-11988=0

a) 136.68+16.272

=136.68+16.4.68

=136.68+64.68

=68.(136+64)

=68.200

= 68.2.100

=136.100 = 13600

b) 36.333-108.111

=36.3.111-108.111

=108.111-108.111

=0

☆★☆★☆

a) 136.68+16.272

=136.68+16.4.68

=136.68+64.68

=68.(136+64)

=68.200

= 68.2.100

=136.100 = 13600

b) 36.333-108.111

=36.3.111-108.111

=108.111-108.111

=0

 khi được tin quân Mông Cổ chuẩn bị xâm lược, nhà Trần đã lệnh cho cả nước sắm sửa vũ khí, các đội dân binh được thành lập, ngày đêm luyện tập võ nghệ, sẵn sàng đánh giặc.

- Nhân dân Thăng Long theo lệnh vua thực hiện chủ trương “vườn không nhà trống”, 

- Trước thế giặc mạnh, tàn bạo, vua Trần hỏi Thái sư Trần Thủ Độ. Ông trả lời: “Đầu thần chưa rơi xuống đất, xin bệ hạ đừng lo”.

- Khi chiếm đóng kinh thành, quân giặc thiếu thốn lương thực trầm trọng, phải cho quân lính đi cướp thóc gạo, hoa màu của dân, nhưng nhân dân các làng, xã đã chống trả quyết liệt làm tiêu hao sinh lực địch.

Khi biết khối lượng:

P=10.m

Khi biết trọng lượng:

m=P:10

Does your father playing with children?  nhé

Does your father playing with children ?

is your father ...

ĐKXĐ: \(x\notin\left\{-7;3;-3\right\}\)

a) Ta có: \(B=\left(\dfrac{x^2+1}{x^2-9}-\dfrac{x}{x+3}+\dfrac{5}{x-3}\right):\left(\dfrac{2x+10}{x+3}-1\right)\)

\(=\left(\dfrac{x^2+1}{\left(x-3\right)\left(x+3\right)}-\dfrac{x\left(x-3\right)}{\left(x+3\right)\left(x-3\right)}+\dfrac{5\left(x+3\right)}{\left(x-3\right)\left(x+3\right)}\right):\left(\dfrac{2x+10}{x+3}-\dfrac{x+3}{x+3}\right)\)

\(=\dfrac{x^2+1-x^2+3x+5x+15}{\left(x-3\right)\left(x+3\right)}:\dfrac{2x+10-x-3}{x+3}\)

\(=\dfrac{8x+16}{\left(x-3\right)\left(x+3\right)}\cdot\dfrac{x+3}{x+7}\)

\(=\dfrac{8x+16}{\left(x-3\right)\left(x+7\right)}\)

b) Ta có: |x-1|=2

\(\Leftrightarrow\left[{}\begin{matrix}x-1=2\\x-1=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\left(loại\right)\\x=-1\left(nhận\right)\end{matrix}\right.\)

Thay x=-1 vào biểu thức \(B=\dfrac{8x+16}{\left(x-3\right)\left(x+7\right)}\), ta được:

\(B=\dfrac{8\cdot\left(-1\right)+16}{\left(-1-3\right)\left(-1+7\right)}=\dfrac{-8+16}{-4\cdot6}=\dfrac{8}{-24}=\dfrac{-1}{3}\)

Vậy: Khi x=-1 thì \(B=\dfrac{-1}{3}\)

c) Để \(B=\dfrac{x+5}{6}\) thì \(=\dfrac{8x+16}{\left(x-3\right)\left(x+7\right)}=\dfrac{x+5}{6}\)

\(\Leftrightarrow6\left(8x+16\right)=\left(x+5\right)\left(x-3\right)\left(x+7\right)\)

\(\Leftrightarrow48x+96=\left(x^2-3x+5x-15\right)\left(x+7\right)\)

\(\Leftrightarrow\left(x^2+2x-15\right)\left(x+7\right)=48x+96\)

\(\Leftrightarrow x^3+7x^2+2x^2+14x-15x-105-48x-96=0\)

\(\Leftrightarrow x^3+9x^2-49x-201=0\)

\(\Leftrightarrow x^3+3x^2+6x^2+18x-67x-201=0\)

\(\Leftrightarrow x^2\left(x+3\right)+6x\left(x+3\right)-67\left(x+3\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left(x^2+6x-67\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left(x^2+6x+9-76\right)=0\)

\(\Leftrightarrow\left(x+3\right)\left[\left(x+3\right)^2-76\right]=0\)

\(\Leftrightarrow\left(x+3\right)\left(x+3-2\sqrt{19}\right)\left(x+3+2\sqrt{19}\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x+3=0\\x+3-2\sqrt{19}=0\\x+3+2\sqrt{19}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-3\left(loại\right)\\x=2\sqrt{19}-3\left(nhận\right)\\x=-2\sqrt{19}-3\left(nhận\right)\end{matrix}\right.\)

Vậy: Để \(B=\dfrac{x+5}{6}\) thì \(x\in\left\{2\sqrt{19}-3;-2\sqrt{19}-3\right\}\)

a: \(=\left(\dfrac{10}{3}+\dfrac{5}{2}\right):\left(\dfrac{19}{6}-\dfrac{21}{5}\right)-\dfrac{11}{31}\)

\(=\dfrac{35}{6}:\dfrac{95-126}{30}-\dfrac{11}{31}\)

\(=\dfrac{35}{6}\cdot\dfrac{30}{-31}-\dfrac{11}{31}\)

\(=\dfrac{-35\cdot5}{31}-\dfrac{11}{31}=\dfrac{-186}{31}=-6\)

b: \(=\left(-8\right)\cdot\dfrac{1}{2}:\left(\dfrac{9}{4}-\dfrac{7}{6}\right)=-4:\dfrac{27-14}{12}=\dfrac{-4\cdot12}{13}=\dfrac{-48}{13}\)

phép tính đầu kết quả là -6

phếp tính thứ 2 kết quả là-48/13

1. Nam (never / eat) _____hasn't eaten__________ pizza before.
2. He (study) _______has studied_________ English for two hours every day.
3. Khoa (like) _____likes__________ omelette very much. It’s his favorite food.
4. My grandmother hates (eat) ____eating___________ noodles. She prefers rice.
5. Thanh (study) ________is studying_______ Physics at the moment.
6. I can’t sleep because the children (play) _______ play________ the drum in the living room.
7. I enjoy (fish) ___fishing____________ because it (be) ______is____________ relaxing.
8. I think, in the future people (not play) ____won't play____ individual games.
9. We find (arrange) ______arranging_________ flowers interesting because it (help) ______helps_________ us relax.
10. I (not collect) _______won't collect________ dolls when I grow up.
11. ______Have_________ Lan (do) _____done__________ her project yet?
12. ________Have_______ you ever (eat) ______eaten_________ Sushi?
13. We (go) _____went__________ to that village to do volunteer work last week.
14. Tom (call) ________called_______ his boss yesterday.
15. She often (go) ____Does she often___________ to the market with her mother once a week?
16. We (visit) ___are going to visit____________ Ha Noi next month.
17. Lan and her father (visit) _______visited________ the Temple of Literature 2 weeks ago.
18. They (not start) _______haven't started________ the project yet.
19. I (have read) _____have read__________ that novel by Hemingway several times.
20. I think in the future, people (explore) ______will explore_________ the nature in stead of watching T.V

Giúp chỗ nào >?

giup j zay bn

Tren duong thang xx' lay diem O .tren cung mot nua mat phang bo la duong thang xx' ve 3 tia Oy,Ot,Oz sao cho goc x'oy =40 độ, xOt =97 độ  xoz=54 độ 

chung minh ot la phan giac cua xoy