Answer:
[tex]f^{-1}(x)=\frac{1}{4} x-\frac{5}{4} [/tex]
Step-by-step explanation:
make [tex]x[/tex] the subject:
[tex]y=4x+5[/tex]
⇒ [tex]4x=y-5[/tex]
⇒ [tex]x=\frac{1}{4} y-\frac{5}{4} [/tex]
change y to x:
[tex]f^{-1}(x)=\frac{1}{4} x-\frac{5}{4} [/tex]