Explanation:
We can find the slope of a line through the formula
Where x1 and y1 are the coordinates of the first point, and x2 and y2 are the coordinates of the second point.
So we substitute the values we are given into this formula:
and simplify:
and simplify again:
And so the slope of line k is 1/2x. Since line p is parallel to line k, the slope of line p is also 1/2x.