Let:
[tex]\begin{gathered} P(n)=y \\ y=0.2n+5.3 \end{gathered}[/tex][tex]n=0.2y+5.3[/tex]
Solve for y:
[tex]\begin{gathered} y=\frac{n-5.3}{0.2} \\ so\colon \\ P^{-1}(n)=\frac{n-5.3}{0.2} \end{gathered}[/tex]
(a)
The amount of vitamins (in grams) for a price of x dollars
(b)
[tex]P^{-1}(x)=\frac{x-5.3}{0.2}[/tex]
(c)
[tex]\begin{gathered} P^{-1}(6.6)=\frac{6.6-5.3}{0.2} \\ P^{-1}(6.6)=\frac{1.3}{0.2} \\ P^{-1}(6.6)=6.5 \end{gathered}[/tex]
