Since Point A represents an elevation below sea level, it will have a negative value on the number line. Let's denote the value of Point A as

, where
is a positive distance below sea level.

Point B is plotted above 0 at a distance exactly equal to the distance of Point A from 0. Since Point A is
, its distance from 0 is
. Therefore, Point B must be positioned
units above 0, which gives it a positive value.

Thus, we can express the value of Point B as
. In summary:

Point A is below sea level and negative (e.g.,
if
).
Point B is directly above sea level and positive, at the same numerical distance from 0 (e.g.,
if
).
Point B is the positive counterpart of Point A in terms of distance from 0 on the number line.

1 answer

Let's denote the elevation of Point A, which is below sea level, as \( -d \), where \( d \) is a positive distance below sea level. Therefore, Point A can be represented as:

\[ \text{Point A} = -d \]

Given that Point B is plotted above 0 at a distance exactly equal to the distance of Point A from 0, we can determine the distance of Point A from 0. The distance from 0 to Point A is:

\[ \text{Distance of Point A from 0} = | -d | = d \]

As Point B is positioned \( d \) units above 0, we find the elevation of Point B to be:

\[ \text{Point B} = 0 + d = d \]

Thus, we can summarize the relationships between Points A and B:

  • Point A is below sea level and negative, for example, \( -d \) if \( d = 500 \) would be \( -500 \).
  • Point B is directly above sea level and positive, at the same numerical distance from 0, for example, \( d \) would be \( 500 \).
  • Point B is the positive counterpart of Point A in terms of distance from 0 on the number line.

In conclusion, the values can be summarized as follows:

  • \( \text{Point A} = -d \)
  • \( \text{Point B} = d \)