From the statement of the problem, we know that.
• Andrea lives 5 1/2 blocks to the west of school → x = -5.5,
,• Ben lives 4 blocks to the east of school → x = +4,
,• Christine lives 2 blocks to the west of school → x = -2,
,• Doug lives 6 1/2 blocks to the east of school → x = +6.5.
A) Using the data above, we have:
B) The x coordinate of:
• Andrea is x_A = -5.5,
,• Ben is x_B = +4.
The distance between Ben and Andrea is equal to the difference between its coordinates:
[tex]d=x_B-x_A=4-(-5.5)=4+5.5=9.5.[/tex]We find that Ben lives 9.5 blocks from Andrea.