Answer:
[tex]f^{-1}[/tex](x) = [tex]\frac{3-x}{3}[/tex]
Step-by-step explanation:
Let y = f(x) and rearrange making x the subject, that is
y = - 3x + 3 ( add 3x to both sides )
3x + y = 3 ( subtract y from both sides )
3x = 3 - y ( divide both sides by 3 )
x = [tex]\frac{3-y}{3}[/tex]
Change x back into terms of y
[tex]f^{-1}[/tex](x) = [tex]\frac{3-x}{3}[/tex]
