Step-by-step explanation:
[tex]f(n) = \frac{ n +4}{2} \\ let \: f(n) = y \implies \: n = {f}^{ - 1}(y) \\ \therefore \: y = \frac{ n +4}{2} \\ \\ \therefore \:2 y = n +4 \\ \\ \therefore \:2 y - 4= n \\ \therefore \:n = 2y - 4 \\ \\ \therefore \: {f}^{ - 1}(y) = 2y - 4 \\ \\ \red{ \boxed{\bold{\therefore \: {f}^{ - 1}(n) = 2n- 4} }}[/tex]
(Replacing y by n)
