Question

Show that points $A(4,2)B(7,5)C(9,7)$ are collinear.

Answer 1

$A(4,,2),B(7,5),C(9,7)$

Collinear points

$AB=(4,2)(7,5),x_1=4,y_1=2$

$x_2=7,y_2=5$

$AB=\frac{y_2-y_1}{x_2-x_1}=\frac{5-2}{7-4}=\frac{3}{3}=1$

$BC=(7,5)(9,7)$

= Same as use formula

$=\frac{7-5}{9-7}=\frac{2}{2}=1$

$CA=(9,7)(4,2)$

$=\frac{2-7}{4-9}=\frac{-5}{-5}=1$

Hence the

$AB=BC=CA$ is collinear