Gọi 2 số đó là a và b (a,b∈Z)
Theo bài ra, ta có:
\(ab=a-b\Leftrightarrow ab+b=a\Leftrightarrow b\left(a+1\right)=a\)
\(\Leftrightarrow\frac{a}{a+1}=b\)
Mà b∈Z \(\Rightarrow\frac{a}{a+1}\)∈Z\(\Rightarrow\frac{a+1-1}{a+1}\)∈Z
\(\Rightarrow1-\frac{1}{a+1}\)∈Z
\(\Rightarrow\frac{1}{a+1}\)∈Z
\(\Rightarrow1⋮\left(a+1\right)\Rightarrow a+1\text{∈}Ư\left(1\right)=\left\{-1;1\right\}\)
\(\Rightarrow a\text{∈{-2;0}}\)
Nếu \(a=-2\)
\(\Rightarrow b=2\left(TM\right)\)
Nếu \(a=0\)
\(\Rightarrow b=0\left(TM\right)\)
