We need to reflect the points: A(-4, -2), B(-1, -1) and C(-1, -4). Across the line y=-x.
When a set of points is reflected across a line their distance to the line must be the same, but they should switch sides across the line. Therefore the coordinates of a point reflected across y=-x, must be:
[tex]P^{\prime}=(-y,-x)[/tex]
With this we can calculated the new coordinates for each point.
[tex]\begin{gathered} A^{\prime}=(2,4) \\ B^{\prime}=(1,1) \\ C^{\prime}=(4,1) \end{gathered}[/tex]
