What methods could you use to calculate the x coordinate of the midpoint of a horizontal segment with the endpoints of -6 0 and 6 0?

You could use algebra (see below for how to do that), or you could graph the line and measure it.

Using algebraThe x-coordinate of the midpoint of a line segment is the average of the x-coordinates of the end-points.

1/2(-6 + 6) = 0

The y-coordinate of the midpoint of a line segment is the average of the y-coordinates of the end-points.

1/2(0 + 0) = 0

The midpoint of the given horizontal segment is the origin, (0, 0) .