Question

Find b given that A (-6, 2), B (b, 0), and C (3,-4) are collinear.

Answer 1

b = -3.

Explanation:

If the 3 points are collinear then:

Slope of AB = Slope of BC and so

(0-2)/(b + 6) = (-4-0)/( 3 - b)

-4(b + 6) = -2(3 - b)

-4b - 24 = -6 + 2b

-24 + 6 = 2b + 4b

6b = -18

b = -3.