Question

How many lines are there which are parallel to X-axis and having a distance 5 units?​

Answer 1

The line x = a is parallel to the Y-axis passing through (a, 0).

If a > 0, then the line will be a distance of a units to the right of the Y-axis.

If a < 0, then the line will be a distance of a units to the left of the Y-axis.

Thus, the distance between the Y-axis and the line x = a is |a| units.