Question

Suppose that A and B are points on the number line.If AB= 14 and B lies at 7, where could A be located?If there is more than one location, separate them with commas.

Answer 1

There are 2 points where A can be located in a number line.

The first case is that A is further ahead than B, and the second case is that A is further back than B:

For case 1:

$\begin{gathered} A-B=14 \\ A-7=14 \\ A=14+7 \\ A=21 \end{gathered}$

For case 2:

$\begin{gathered} B-A=14 \\ 7-A=14 \\ 7-14=A \\ -7=A \end{gathered}$

The 2 possible points for A are -7 and 21