Find the missing value. Hint: Use the number line to find the missing value.
-4 -
9
{
--15
开
15
-10
-5
0
5
10

Quadrilateral ghij has coordinates g(5, 1), h(4, -3), i(6, -1), and j(2, 1). if the quadrilateral is reflected over the line y = x, what are the coordinates of h'?