Respuesta :

set f(x) equal to y

y = 5x + 4

swap x and y

x = 5y + 4

make y the subject

x - 4 = 5y

[tex]y = \frac{x - 4}{5} [/tex]

replace y with f^-1(x)

[tex]f(x) = \frac{x - 4}{5} [/tex]