Answer
Less than $200$ miles per day will make a basic rental a better deal than an Acme rental.
Work Step by Step
Let us suppose $x$ is the number of miles driven per day; the daily cost of the basic car is less than the daily cost of the Acme rental, that is, $30+0.05x$.
Now,
$20+0.10x<30+0.05x$
To solve the inequality, subtract $0.05x$ from both sides.
Then,
$\begin{align}
& 20+0.10x-0.05x<30+0.05x-0.05x \\
& 20+0.05x<30
\end{align}$
Then, simplify,
$\begin{align}
& 20+0.05x-20<30-20 \\
& 0.05x<10
\end{align}$
$x\lt 200$
