well, since y is the dependent variable and x the independent, let's pick any three random values for x to get y.
let's say x = 2
-y = (2)+0
y = -2.................................. (2, -2)
let's say x = 3
-y = (3) + 0
y = -3.................................. (3, -3)
let's say x = 7
-y = (7) + 0
y = -7.................................. (7, -7)
so we have three points, check the picture below.
