Question

Find the value of x for which the points (x, – 1), (2,1) and (4, 5) are collinear.

Answer 1

Solution:
Let the points be A(x, -1), B(2, 1) and C(4, 5)

Now as the points are collinear, therefore

mAB = MBC

2 = 2(2 – x) = 4 – 2x

or 2x = 4 – 2

⇒ 2x = 2 ⇒ x = 1