Question

Find K such that the points (-2, 5), (2, 8) and (6, K) are collinear.

Answer 1

k = 11

Explanation:

let the points be A(-2,5), B(2,8), C(6,K).

for the points to be collinear slope of line AB maust be equal to line BC.

slope of line AB =
`(8-5)/(2+2)=(3)/(4)`

slope of line BC =
`(k-8)/(6-2)=(k-8)/(4)`

therefore
`(k-8)/(4)= (3)/(4)`

therefore k = 8 + 3

k = 11