`a/b = \frac{a(b+2001)}{b(b+2001)} = \frac{ab + 2001a}{b(b+2001)}`
`\frac{a+2001}{b+2001} = \frac{b(a+2001)}{b(b+2001)} = \frac{ab + 2001b}{b(b+2001)}`
Nếu` a > b => ab + 2001a > ab + 2001b => \frac{ab + 2001a}{b(b+2001)} > \frac{ab + 2001b}{b(b+2001)}`
Nếu `a < b => ab + 2001a < ab + 2001b => \frac{ab + 2001b}{b(b+2001)} > \frac{ab + 2001a}{b(b+2001)}`
Nếu `a = b => ab + 2001a = ab + 2001b => \frac{ab + 2001a}{b(b+2001)} = \frac{ab + 2001b}{b(b+2001)} `
