Tìm x,y ∈ ℤ , biết: |x + 25| + |– y + 5| = 0

|x + 25| + |– y + 5| = 0

⇔ \(\left[ \begin{array}{l}\left| {x + 25} \right| = 0\\\left| { - y + 5} \right| = 0\end{array} \right.\)

⇔ \(\left[ \begin{array}{l}\left| {x + 25} \right| = 0\\\left| { - y + 5} \right| = 0\end{array} \right.\)

⇔ \(\left[ \begin{array}{l}x = - 25\\y = 5\end{array} \right.\)

Vậy (x;y) = (-25;5).