We knowt that,
The distance of any point from the x-axis is the perpendicular dropped from that point to the x-axis.
Similarly,
The distance of any point from the y-axis is the perpendicular dropped from that point to the y-axis.
Therefore, for point D (7, 4)
distance from x-axis is 7 units and
distance from y-axis is 4 units.
And, for point C (-3, 6)
distance from x-axis is 3 units and
distance from y-axis is 6 units.