Answer:
y = -6
Explanation:
On the coordinate plane, the vertical axis (up and down) is the y-axis and the horizontal axis (side to side) is the x-axis. However, when there is a horizontal line on the graph, it represents a value of y that is true for any value of 'x'. In the same respect, a vertical line is a value of x that is true for any value of 'y'. In the case of the point (5, -6), a horizontal line would have to be y = -6 in order to pass through the point and cross the coordinate plane from left to right.