Write an equation for the data values below

x -4 -3 -2 -1
y -1 0 1 2

x goes up 1 (-4to-3), y goes up 1(-1 to 0)

x goes up 3(-4 to-1), y goes up 3(-1 to 2)

change in / change in x = slope = 1

so y = m x + b with m = 1
y = x + b
put in a point (-3,0) is easy
0 = -3 + b
b = 3
so
y = x + 3