+) Nếu \(x \ge \frac{1}{2}\) thì \(y = 2x - 1 - 3 - x = x - 4\).
+) Nếu \( - 3 < x < \frac{1}{2}\) thì \(y = - 2x + 1 - 3 - x = - 3x - 2\).
+) Nếu \(x \le - 3\) thì \(y = - 2x + 1 + 3 + x = - x + 4\).
Vậy \(y = \left\{ \begin{array}{l}x - 4\,khi\,x \ge \frac{1}{2}\\ - 3x - 2\,khi\, - 3 < x < \frac{1}{2}\\ - x + 4\,khi\,x \le - 3\end{array} \right.\).
Vẽ đồ thị:
