Question

What value of x makes the relation {(1,5),(x,8),(-7,9)} a function?

Answer 1

`x=-5`

Explanation:

If this relation constitutes a linear relation, I must equate 2 equations for 2 points. Hence,

`(8-5)/(x-1)=(9-5)/(-7-1)`

`3/(x-1)=4/(-8)`

`3/(x-1)=-1/2`

`x-1=-6`

`x=-5`