Think of two points on a straight line. The first point is (0,8) representing 8 employees at time 0. The second point is (6,26), representing 26 employees after six months have gone by.
26-8
The slope of this line is m = ---------- = 18/6 = 3
6-0
This indicates that 3 new employees are taken on on average each month.
This situation can be represented as
E(x) = 8 + 3x, where x is the number of months that have passed, and E(x)
represents the number of employees at that point in time.