tìm giá trị lớn nhất:

M = 6x - x \(^2\) - 5

N = 5 - 4x\(^2\) + 4x

P = -x\(^2\) - 4x - y\(^2\) + 2y

tìm giá trị nhỏ nhất :

A = x\(^2\) +4x + 5

B = x\(^2\) + 5x + 7

C = ( x - 1)(x - 3) + 11

Chứng minh rằng với mọi n thuộc Z thì:

a) (n + 2)\(^2\) - (n - 2)\(^2\) chia hết cho 8

b) (n + 7)\(^2\) - (n - 5)\(^2\) chia hết cho 24

cho hình vuông ABCD. gọi E là điểm đối xứng vs A qua D.

a) CM ACE vuông cân

b) kẻ AH ⊥ BE, M và N là trung điểm của AH và HE. cm BMNC là hbh

c) M là trực tâm của ΔABC

d) Chứng minh góc ANC = 90\(^o\)

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.

"I am sorry, I forgot our appointment yesterday," said Jean to the dentist.

A. Jean apologized the dentist for having forgotten our appointment the day before. 

B. Jean apologized to the dentist for having forgotten their appointment the day before. 

C. Jean apologized the dentist having forgotten their appointment the day before. 

D. Jean apologized to the dentist for having forgotten our appointment the day before.

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.

People say he won a lot of money on the lottery.

A. He is said to have won a lot of money on the lottery. 

B. He was said to win a lot of money on the lottery. 

C. He is said that he won a lot of money on the lottery. 

D. He won a lot of money on the lottery, it is said.