1,3 . (-4,6) + 1,3 . (-5,4) = 1,3 . [-4,6 + (-5,4)]

= 1,3 . ( -10) = -13 

A

It was reported that there were two people injured in the accident.

A = 2x² + 2x + 2xy + y² + 2

A = x² + 2xy +y² + x² + 2x + 1 + 1

A = (x + y)² + (x + 1)² + 1 \(\ge\) 1 > 0

=> A > 0    ( \(\forall\) x,y)

=> đpcm 

cho mình hỏi, câu 2 là "clean" hay "cleaning"? 

1. Why don't you play with her?

2. Is the maid cleaning the floor? 

(x - 2)(x² + 2x + 4) + 2(x² - 4) - 5(x - 2) = 0

(x - 2)(x + 2)² + 2(x - 2)(x+2) - 5(x - 2) = 0

(x - 2)[(x+2)² + 2(x+2) - 5]= 0

(x - 2)[(x + 2)² + 2(x + 2) + 1 - 6] = 0

( x - 2)[(x + 2 + 1)² - 6] = 0

(x - 2)[(x + 3)² - 6] = 0

(x - 2)(x + 3 - \(\sqrt{6}\))(x + 3 + \(\sqrt{6}\)) = 0

TH1. x - 2 = 0 <=> x = 2

TH2. x + 3 - \(\sqrt{6}\) = 0 <=> x = \(\sqrt{6}-3\)

TH3. x + 3 + \(\sqrt{6}\) = 0 <=> x = \(-\sqrt{6}-3\)

S = {2; \(\sqrt{6}-3\); \(-\sqrt{6}-3\)}

Lan started writing / to write to her penfriend 3 years ago

18. We clean our __________ before Tet.

A. a wish         B. luckey money                   C. fireworks                    D. furniture

19. It’s raining heavily outside, so we ___________ go out.

A.Will B. should C. shouldn’t D. can

20. My mother usually __________ traditional food on special days.

A. cooks  B. cook C. cookes                    D. cooking

* Choose the word or phrase (A, B, C or D) that needs correcting.

1 This dress is expensiver than that one.

A. This dress         B. is                   C. expensiver D. that one

2. Children should break things at Tet.

A.  Children B. should C. break things D. at

3. What about plant in the garden?  

A. What B. plant C. in D. garden

4. Winter is cold than spring

A. Winter B. is C. cold D. than

* Mark the letter A, B, C or D to indicate the most suitable response.

1. Lan: “My class has won the aerobics contest.”

    Mai:  “________________________”

A. Good luck! B. Congratulations!   C. See you later. D. Goodbye

2. Tom: "Hello, Mary. Wishing you laughter from January to December ." 

     Mary: “________________________.”

A. Hi, Tom. Wishing you happyness and cheer.             B. Hello, thanks?

C. Hi. Thank you.                                       D. Yes, I'd love to. Thanks

3. Tom: " Let’s meet at 10 o’clock.?"

     Mary: “________________________.”

A. Nice to meet you B. I am busy to meet you. 

C. Sure. I’ll meet you at that time.               D. It is nice. Thank you.