Question

The points (K, 3), (2, −4) and (−K + 1, −2) are collinear. Find K.

Answer 1

Given, points A(K, 3), B(2, −4) and C(−K + 1, −2) are collinear.

∴ Slope of AB = Slope of BC

`(-4 - 3)/(2 - k) = (-2 + 4)/(-k + 1 - 2)`

`(-7)/(2 - k) = 2/(-k - 1)`

7k + 7 = 4 − 2k

9k = −3

`k = (-1)/3`