If a line pass through three points, they are collinear points, and the determinant of a matrix produced by their coordinates equals 0.
Knowing this, we can fin the value of n.
We need a triangular matrix, so we can complete it with 1's.
\(\left[\begin{array}{ccc}6&3&1\\8&4&1\
&-2&1\end{array}\right]\)
24 + 3n - 16 - 4n + 12 - 24 = 0
- n - 4 = 0
- n = 4
n = -4
The value of n it's -4.
Hope it helps.
