A và D nha

tick mik vs

tick kieu j ban

A=(n-2)/(n+3)= (n-3+5)/(n-3)= 1+ 5/(n-3) 
Để biểu thức A lớn nhất thì 1+ 5/(n-3) LN. Mà 1>0; 1 ko đổi => 5/(n-3) LN. 5>0; 5 ko đổi=> n-3 nhỏ nhất, n-3>0. Mà n thuộc Z nên n-3 thuộc Z=> n-3=1 => n=4 
Khi đó A =4+2/4-3= 6/1=6

a, với n thuộc Z

Để A là một số nguyên thì 3n + 1 chia hết cho n+1

                               mà n + 1 chia hết n +1

=> (3n+1) - 3. (n+1) chia hết cho n+1

<=> (3n+1)-( 3n +3) chia hết cho n+1

<=> 4 chia hết cho n+1

=> n+1 thuộc Ư(4)= {+-1; +-4; +-2}

nếu ............

\(a)\) Để A là phân số thì \(n-5\ne0\) 

\(\Rightarrow\)\(n\ne5\)

Vậy để A là phân số thì \(n\ne5\)

\(b)\) Ta có : 

\(A=\frac{n+2}{n-5}=\frac{n-5+7}{n-5}=\frac{n-5}{n-5}+\frac{7}{n-5}=1+\frac{7}{n-5}\)

Để A có giá trị nguyên thì \(\frac{7}{n-5}\) phải có giá trị nguyên 

\(\Rightarrow\)\(7\) chia hết cho \(n-5\)

\(\Rightarrow\)\(\left(n-5\right)\inƯ\left(7\right)\)

Mà \(Ư\left(7\right)=\left\{1;-1;7;-7\right\}\)

Suy ra : 

Vậy để A có giá trị nguyên thì \(n\in\left\{-2;4;6;12\right\}\)

Chúc em học tốt ~ 

THÕA MÃN ĐK LÀ:\(n-3\ne0\Rightarrow n\ne3\)

                            \(5-n\ne0\Rightarrow n\ne5\)

????? đây là Tiếng Anh mà sao lại Toán ???????????

Tôi đến chịu với bn, tất cả là tiếng việt chữ nghĩa rõ ràng mà

Đặt 5 câu thích ( không dùng từ love ; ) trong các vế sau

S + enjoy/prefer + Ving/N

vd:They enjoy/prefer eating rice.

S + do not / dose not + enjoy + Ving/N

  vd:I don't enjoy playing badminton

+ S + be + keen on + Ving/N

vd:She is keen on going swimming

- S + be + not + keen on +Ving/N

vd: He is not keen on doing aerobics

Trả lời:

I enjoy that cake with my friend

Dạng câu phủ định ta có:

Does you enjoy the party

Dạng khẳng định:

+ I'm a student.
+ He's a teacher.
+ They are workers.
+ She is rude.
+ It is beautiful.

I don't drink milk

Đối vố S = be +keen ta dùng

–    I’m keen on/ cycling.

Tôi ham thích đạp xe.

(Không dùng *It s me the cycling*, *keen to cycling /cycle*)

–    I can’t drive yet. but I’m keen to learn.

P.s:Hok tốt

Xem kĩ tại link này:https://toomva.com/post/cau-truc-cau-khang-dinh-phu-dinh-nghi-van-cua-cac-thi-dung-trong-hien-tai=28

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