Answer :

a) Recall that to evaluate a function at a given value, we substitute the variable by the given value.

Therefore, evaluating C(h) at h=6 we get:

[tex]C(6)=76+24\cdot6.[/tex]

Simplifying the above result we get:

[tex]\begin{gathered} C(6)=76+144 \\ =220. \end{gathered}[/tex]

b) Setting C(h)=364 we get:

[tex]76+24h=364.[/tex]

Subtracting 76 from the above equation we get:

[tex]\begin{gathered} 76+24h-76=364-76, \\ 24h=288. \end{gathered}[/tex]

Dividing the above equation by 24 we get:

[tex]\begin{gathered} \frac{24h}{24}=\frac{288}{24}, \\ h=12. \end{gathered}[/tex]

Answer:

(a) $220.

(b) 12.