The reflection line is located at y = -x
For point J, x is -2, so y = -(-2), which equals 2.
When it is a reflection across Y, the X values remain the same.
Find the distance of the Y point to the reflection line,
The distance from -1 to 2 is 3 units.
The new point needs to be the same distance from the reflection line.
2 + 3 units = 5.
Point J' would be (-2,5)