A
evaluate f(5) and f(2)
f(5) = 5m + b and f(2) = 2m + b, hence
f(5) - f(2) = 5m + b - 2m - b = 3m
the expression simplifies to
[tex]\frac{3m}{3}[/tex] = 2 ( cross- multiply )
3m = 6 ( divide both sides by 3 )
m = 2 → A
