SOLUTION: Find the value of k so that the line containing the points (3,k) and (−3,4) is perpendicular to the line containing the points (−7,1) and (−1,2).

Algebra ->  Linear-equations -> SOLUTION: Find the value of k so that the line containing the points (3,k) and (−3,4) is perpendicular to the line containing the points (−7,1) and (−1,2).      Log On


   

Question 785281: Find the value of k so that the line containing the points (3,k) and (−3,4) is perpendicular to the line containing the points (−7,1) and (−1,2).
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
The slope of the line containing the points (−7,1) and (−1,2) is
%282-1%29%2F%28-1-%28-7%29%29=1%2F%28-1%2B7%29=1%2F6
The slope of the line containing the points (3,k) and (−3,4) is
%28k-4%29%2F%283-%28-3%29%29=%28k-4%29%2F%283%2B3%29=%28k-4%29%2F6
For two lines to be perpendicular, the product of their slopes must be -1.
%281%2F6%29%2A%28%28k-4%29%2F6%29=-1
%28k-4%29%2F36=-1
k-4=-36
k=-36%2B4
highlight%28k=-32%29