Can you help me with this exercise?
The fuel efficiency E depends on the speed $s$ of the mobile phone. A car travels at $100\%$ fuel efficiency when traveling at $55$ miles per hour ($MPH$). Suppose that the fuel efficiency in percent is given by the following equation, which is a function of the fuel speed $(s)$ in $(MPH)$:
$$E(s)=-0.033058(s^2-110s)$$
If you want the car to travel at least $95\%$ efficient, how close to $55~MPH$ should you drive?
Thanks
Solve the quadratic equation to get interval around 55 mph $$0.033058s^2 - 3.63638s + 95 = 0$$