3. In a quadratic trinomial, the second coefficient and the constant term were swapped, after which the result was added to the original trinomial. This resulted in a third quadratic trinomial, which turned out to have a single root. What can this root be equal to? If there are multiple correct answers, list them separated by a semicolon.
Answer: $0 ;-2\|0,-2\|-2 ; 0$

## Examples of writing answers:

14

$1 / 4$

0, $25 ; 0,5$