Ta có : $\frac{n+1}{n-2}$ = $\frac{n-2+3}{n-2}$ = 1 + $\frac{3}{n-2}$ 

a, A có giá trị nguyên khi n + 1 chia hết cho n - 2 ⇔ 3 chia hết cho n - 2 

⇒ n - 2 ∈ Ư ( 3 ) = { ± 1 ; ± 3 }

⇒ n ∈ { 1 ; 3 ; - 1 ; 5 }

Bài 2:

\(\text{Vậy tập hợp giá trị của x là:}\) 

\(\dfrac{13}{35}=\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{35}\)

\(\text{Mỗi ngày xưởng đó đóng gói:}\)

\(17350:5=3479\left(hộp\right)bánh\)

\(Đápsố:3470hộpbánh\)

\(\text{x=20+5=25}\)

I am hungry. 

It is warm today.

  My hands are cold.

  Canada is a very big country

  Rome is not in Spain.

  He is not at work. 

Scarlett is not my sister.

  Are the shops open today? 

Is the post office near here?

  Are your kids at school? 

The candies are not delicious.

Mai is not your sister.

  She cooks dinner every day.

  Does the flower smell good? 

Did you eat lunch today?

  I am not eating seafood.