For this case we have that by definition, the slope of a line is given by:
[tex]m = \frac {y_ {2} -y_ {1}} {x_ {2} -x_ {1}}[/tex]
According to the statement we have the following data:
[tex](x_ {1}, y_ {1}): (- 4,5)\\(x_ {2}, y_ {2}) :( r, 3)\\m = - \frac {2} {5}[/tex]
Substituting we have:
[tex]- \frac {2} {5} = \frac {3-5} {r - (- 4)}\\- \frac {2} {5} = \frac {-2} {r + 4}[/tex]
So we have to:
[tex]r + 4 = 5\\r = 5-4\\r = 1[/tex]
Thus:
[tex]x_ {2} = 1[/tex]
ANswer:
[tex]x_ {2} = r = 1[/tex]
