Answer:
Let X represent Nick's age and Y represent Sara's age.
Then, it is given that: Nick is four years older than Sara.
We write the statement as:
[tex]X=4+Y[/tex]
or [tex]Y=X-4[/tex]
The only ordered pairs (X,Y) which satisfy the equation are: (0,-4) and (4,0) as you can see in the graph also.
In the graph X axis represents the age of Nick's age and Y-axis represent the age of Sara's age and the line Y=X-4 represents the relationship between the age of both.