Y = -2x + 5
-1: -2(-1) + 5 = 9
1: -2(1) + 5 = 3
3: -2(3) + 5= -1
5: -2(5) + 5= -5
Plot these coordinates on the graph
(-1,9)
(1,3)
(3,-1)
(5,-5)
If the line is straight then it’s linear
If the line has a constant of proportionality the it’s proportional