let's take some ordered pairs that fit the above description.
(25,3.5) , (35, 4.5), (45, 5.5), (15, 2.5 , (5, 1.5)
etc
in each case of pairs, the slope is 1/10 , and the function is linear.
so A = (1/10)m + b
using the given point (25,3.5)
3.5 = (1/10)(25) + b
b = 1
A = (1/10)m + 1