The distances measured along the X-axis from the origin to its right, are considered _____ and the distances measured along the X-axis from the origin to its left are considered _____ by convention.
Positive, Negative
The sign convention was introduced to avoid ambiguity in distances measured on either side of the origin.
The distances that are measured from the origin, of points that lie to its right, are considered positive, and the distances that are measured from the origin, of points that lie to its left, are considered negative.