Answer:
[tex]d^{-1}[/tex](x) = [tex]\frac{x+4}{2}[/tex]
Step-by-step explanation:
let d(x) = y and rearrange making x the subject, that is
2x - 4 = y ( add 4 to both sides )
2x = y + 4 ( divide both sides by 2 )
x = [tex]\frac{y+4}{2}[/tex]
Change y back into terms of x, so
[tex]d^{-1}[/tex](x ) = [tex]\frac{x+4}{2}[/tex]