To solve this problem graphically we need perform the following steps:
Draw the axis and labeled them correctly.
We choose an appropriate scale to represent one meter, for example we can choose 1 cm to represent 50 meters; in that way 500 m will be represented by an arrow with length 10 cm.
We draw an arrow pointing north of 10 cm.
We draw an arrow pointing east of 4 cm from the head of the previous arrow.
We draw an arrow pointing south of 6 cm from the head of the previous arrow.
We draw an arrow pointing west of 8 cm from the head of the previous arrow.
We draw an arrow from the origin to the head of the last arrow.
We measure the horizontal projection of the last arrow and the vertical projection, this will give us the displacement in the x and y direction, respectively.
This is shown in the diagram below:
Therefore, the displacement of Dexter from the origin is -200 m on x and 200 m on y, this can be also said as Dexter is 200 m west and 200 m north from where he began.