A (4, 8), B (5, 12), C (9, 28)Slope of AB = x2​ − x1​y2​ − y1​​ = 5 − 412 − 8​ = 14​ = 4Slope of BC =x2​ − x1​y2​ − y1​​ = 9 − 528 − 12​ = 416​ = 4Since, Slope of AB = Slope of BC = 4Therefore, the given points are collinear.