Question

cho A = x trên x + 3

tìm x thuộc Z để A nguyên

Answer 1

\(A=\dfrac{x}{x+3}=1-\dfrac{3}{x+3}\in Z\)

\(\Rightarrow\left(x+3\right)\inƯ\left(3\right)=\left\{-3;-1;1;3\right\}\)

\(\Rightarrow x\in\left\{-6;-4;-2;0\right\}\)