Question

find the value of k for which the points are collinear.

(i) (7, -2), (5, 1), (3,-k) ​

Answer 1

Answer:

Step-by-step explanation: collinear points have the gradient

Using (3; -k) and (5; 1)

Gradient 1= 1- (-k)/5-3

= 1 + k/2

Using (5; 1) and (7; -2)

Gradient 2= 1- (-2)/5-7

= 1+2/-2

= -3/2

Gradient 1= Gradient 2

1+k/2= -3/2

-2- 2k = 6. Cross multiply

-2k = 6+2

-2k = 8

k= -4