To rotate a point \((x, y)\) 90 degrees counterclockwise about the origin, we can use the following transformation rule:
\[ (x, y) \rightarrow (-y, x) \]
Now, let's apply this rule to the point \( W(-3, 7) \):
- Identify the coordinates: \( x = -3 \) and \( y = 7 \).
- Apply the transformation:
\[ W'(-3, 7) \rightarrow (-7, -3) \]
So the coordinates of \( W' \) after a 90-degree counterclockwise rotation about the origin are:
\[ W'(-7, -3) \]