n={-4,1,2,7} nha bạn

{-4;1;2;7} , ủng hộ mk nha

Để A là số nguyên thì 44 chia hết cho 2n-3

=>2n-3\(\in\)Ư(44)={-44,-22,-11,-4,-2,-1,1,2,4,11,22,44}

=>2n\(\in\){-41,-19,-8,-1,1,2,4,5,7,14,25,47}

Loại các trường hợp 2n={-41,-19,-1,1,5,7,25,47} vì không chia hết cho 2

=>2n\(\in\){-8,2,4,14}

=>n\(\in\){-4,1,2,7}

ta co de A la so nguyen thi 2n-3 thuoc uoc cua 44=1;-1;2;-2;4;-4;11;-11;-22;22

tu thay tung gia tri vao 2n-3 giai ra

44:2n-3 nguyên<=>44 chia hết cho 2n-3

=>2n-3 E Ư(44)={-44;-22;-11;-4;-2;-1;1;2;4;11;22;44}

=>2n E {-41;-19;-8;-1;1;2;4;5;7;14;25;47}

=>n E {-4;1;2;7}

tu giai van tot hon

\(\frac{n}{n+3}\)=\(\frac{n+3-3}{n+3}\)=\(\frac{n+3}{n+3}\)-\(\frac{3}{n+3}\)=1-\(\frac{3}{n+3}\)\(\Rightarrow\)3\(⋮\)n+3\(\Rightarrow\)n+3\(\in\)Ư(3)=\(\left\{-3;-1;1;3\right\}\)

+ n+3=-3\(\Rightarrow\)n=-3-3=-6

+ n+3=-1\(\Rightarrow\)n=-1-3=-4

+ n+3=1\(\Rightarrow\)n=1-3=-2

+n+3=3\(\Rightarrow\)n=3-3=0

Với n \(\in\)(-6;-4;-2;0) thì \(\frac{n}{n+3}\)có giá trị nguyên