Question

Determine an equation. There is a 3rd diffference. Which is -6. a= -1. Some points are (0,0) (-1,-2) (1,2)

Answer 1

This is a str8 line:
(0,0) (-1,-2) (1,2) put these in order and it might be easier to see

(-1,-2) (0 ,0) (1,2)

Answer 2

This part does not make sense to me:
There is a 3rd difference. Which is -6. a= -1
But the above 3 point are on the same line