Point L is at (-3, 6) after a reflection over the y-axis.
With reflections, if the reflection is over the y-axis the y coordinate sign will become opposite of what it was, in this case the negative 6 in the original coordinate pair became a positive six in the new reflected coordinate. If the six in the original coordinate pair was positive, then it would become negative in the new reflected coordinate pair. The same rules apply to a coordinate reflected over the x-axis, only now we are dealing with the x coordinate in the ordered pair. The x coordinate sign will become the opposite of what it originally was.