A horizontal line is a line that runs parallel to the x-axis. The defining characteristic of a horizontal line is that it has a constant y-coordinate for all points along the line.
In the case of the point (8, 7), the y-coordinate is 7. This means that for every x-value, the y-coordinate will always remain 7. Therefore, the equation of the horizontal line that passes through this point can be expressed as:
y = 7
This equation indicates that no matter what value of x you choose (x can be any real number), the value of y will always be 7. So, if you were to draw this line on a graph, it would be a straight line that runs across the page at the height of 7 units from the x-axis.
In conclusion, the equation of the horizontal line that passes through the point (8, 7) is y = 7.