If ( -4,11) (2,-4) and (6,n) are coordinates of points on the same plane line, determine n?

Question

Hi, please help me solve : If ( -4,11) (2,-4) and (6,n) are coordinates of points on the same plane line, determine n?

Answer 1

Using the first two points given, we find that the slope of the line containing them has slope -5/2.

 

Using the last and first points, we calculate the slope as (n-11)/(6-(-4)) = (n-11) / 10.

 

These two slopes must be the same, if all three points are COLLINEAR.

 

The equation setting -5/2 = (n-11)/10 is a proportion, and we cross-multiply: (n-11)(2) = -5(10).

 

The solution is n = -14.  <<<<<< Corrected!