1. **State the problem:**
The band wants to earn 500 by selling posters. The number of posters sold depends on the price per poster $p$ and is given by the expression $-3.5p + 85$.
2. **Write the revenue formula:**
Revenue $R$ is price per poster times number of posters sold:
$$R = p \times (-3.5p + 85)$$
3. **Set revenue equal to 500 and form the quadratic equation:**
$$p(-3.5p + 85) = 500$$
$$-3.5p^2 + 85p = 500$$
4. **Rewrite the equation in standard form:**
$$-3.5p^2 + 85p - 500 = 0$$
5. **Multiply entire equation by $-1$ to simplify:**
$$\cancel{-}3.5p^2 + \cancel{-}85p + \cancel{-}500 = 0 \Rightarrow 3.5p^2 - 85p + 500 = 0$$
6. **Use the quadratic formula:**
$$p = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $a=3.5$, $b=-85$, $c=500$.
7. **Calculate the discriminant:**
$$b^2 - 4ac = (-85)^2 - 4(3.5)(500) = 7225 - 7000 = 225$$
8. **Calculate the roots:**
$$p = \frac{85 \pm \sqrt{225}}{2 \times 3.5} = \frac{85 \pm 15}{7}$$
9. **Find the two possible prices:**
$$p_1 = \frac{85 + 15}{7} = \frac{100}{7} \approx 14.29$$
$$p_2 = \frac{85 - 15}{7} = \frac{70}{7} = 10$$
10. **Interpretation:**
Both prices yield revenue of 500, but the question asks for the highest price per poster.
**Final answer:**
To the nearest dollar, the highest price per poster is **14**.
Poster Price 3008E6
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