The distance between a and n is |a - b| = |b - a|.
Using the definition given above, rewrite the statement using absolute value.
The distance between x and 4 is at least 8.
The distance between x and 4 is | x - 4|.
The |x - 4| is at least 8 can be expressed as
| x - 4| is > or = to 8.
Why must we set |x - 4| to be greater than or equal to 8 and not less than or equal to 8?