Answer:
k = 11
Step-by-step explanation:
Given the points are collinear then the slopes between consecutive points are equal.
Using the slope formula
m =
![(y_(2)-y_(1) )/(x_(2)-x_(1) )](https://img.qammunity.org/2022/formulas/mathematics/high-school/j00l0gv4ukoczmg4cxr4gb77bcnbgeyskh.png)
with (x₁, y₁ ) = (5, 1) and (x₂, y₂ ) = (1, - 1)
m =
=
=
![(1)/(2)](https://img.qammunity.org/2022/formulas/mathematics/high-school/f0qcv9cek84ihznc3s7uf39dlk9xfru67q.png)
Repeat with another 2 points and equate to
![(1)/(2)](https://img.qammunity.org/2022/formulas/mathematics/high-school/f0qcv9cek84ihznc3s7uf39dlk9xfru67q.png)
with (x₁, y₁ ) = (1, - 1) and (x₂, y₂ ) = (k, 4)
m =
, then
=
( cross- multiply )
k - 1 = 10 ( add 1 to both sides )
k = 11