#### Answer

We can drive $860$ miles for $395.

#### Work Step by Step

First. we need to set up an equation that we can solve.
The unknown in this case is the number of miles we can travel if we have $395$. Let us use $x$ to denote this unknown. We will multiply $x$ by $0.25$ to get how much we will be charged for the amount of miles we drive.
The agency will charge us $180$, regardless of how many miles we drive, so $180$ is a constant.
To be able to calculate the charges, we will add $180$ to $0.25x$. We want this amount to equal $395$ because that is the amount we want to spend.
The equation we get is:
$$0.25x + 180 = 395$$
We subtract $180$ from each side of the equation to isolate the variable to one side of the equation:
$$0.25x = 215$$
We divide both sides by $0.25$ to solve for $x$:
$$x = 860$$
We can drive $860$ miles for $395.